Citation Managers and Citing-Cited Data

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	Issues in Science and Technology   Librarianship
	Summer 2002

	DOI:10.5062/F45M63NW



      

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Citation Managers and Citing-Cited Data
      Brian Simboli
  Science Librarian
  Lehigh University
brs4@lehigh.edu      Min Zhang
  Computer Consultant
  Smart IMS, Inc.
miz2@lehigh.edu  

      


       

	Abstract
     There is an increasing trend for library resources to enable  identification of cited and citing reference lists, i.e., lists of items cited  by documents, as well as items that in turn cite those documents. In  this article, we evaluate how two citation managers, EndNote and RefWorks, provide  ways to store, display, and retrieve these lists. Then, we suggest enhancements  with respect to cited and citing reference data that should be adopted by any  citation management software that currently lacks them. Finally, we discuss how  publishers can also do more to facilitate use of citation managers with respect to  these types of data. 

    

Introduction
    An increasing number of electronic library resources enable one to identify not  only literature relevant to one's research, but also documents that cite  -- and are cited by -- that literature. By enabling users to exploit the  potentially tight conceptual nexus between, for example, a journal paper, the  papers it cites, and the papers that (in turn) cite it, these resources enable the  building of more comprehensive bibliographies than would otherwise be possible. We  refer to these as "citing/cited resources" in this article.     The availability of citing/cited resources makes it useful to have efficient,  easy-to-use ways to organize and display such relationships. Current citation  management software ("citation managers") provide some ways to do this. These  capabilities are useful, for example, to authors who track literature that cites  their work or researchers who track a developing body of literature about a new  topic.

    This paper has five sections. The first identifies and discusses a number of citing/cited  resources. The second and third evaluate the current capabilities of two citation managers to  store and display citing/cited relationships between documents.1  The fourth suggests enhancements that would improve the ability of citation managers to  facilitate the use of citing/cited data. The fifth argues that publishers can do more to  promote use of citation managers with respect to the citing and cited reference lists they  provide. 

    

Building Bibliographies Using Citing/Cited Data Resources
     The library research guide titled "{'Cited/Citing Resources:' A Special Way to Build Bibliographies}" identifies and discusses available resources. One category of such resources are databases whose records contain not only the usual bibliographic data and indexing for a document, but also references that the document cites. We will refer to the latter as "cited reference lists."2 Cited reference lists allow one to search on a known document "x" and find documents "y," published later in time, that include document "x" in their reference lists. In turn, taking these newly discovered citing documents "y," one can perform the same operation on each of them to arrive at other documents "z," published later in time, that cite documents "y." Through such iterative bootstrapping, one builds up a bibliography.     ISI has been the longstanding producer of databases providing this capability. But  others, e.g., CAS's SciFinder Scholar and MathSciNet, now offer it as well.   Because SciFinder Scholar offers cited references for bibliographic records added  to the CAS databases from 1999 forward, and MathSciNet offers reference  lists for material from January 2000,3 their ability to  generate lists of citing and cited references is limited. However, as these  databases grow in size over time, their usefulness in searching for citing and  cited relationships will increase. 

    Electronic journals comprise another category of resources that makes it possible  to start with a known reference and find references that cite it. Examples  identified on the web page are Nature, Science, and  Applied Physics Letters. 

    The growing availability of such resources creates an increasing need for efficient ways to  store, organize, and display citing/cited relationships between documents. We now evaluate  the capabilities of two citation managers for doing so:  EndNote and RefWorks. The first  software is downloaded to one's hard drive while the latter is web based. 

    

How EndNote Handles Citing/Cited Data4

    EndNote enables one to download or manually input bibliographic records from  library databases and then store the data in a "library." A library consists of a  set of records containing data about a document (e.g., a journal article). Some of  the fields, such as author, title, and year, for each record can be listed in a  window that comes up when a library is opened. Clicking on a row of the list opens  the corresponding full EndNote record.     One can manually input data into the records that comprise a library or one can use an  "import filter" or "connection file" to draw data from databases into EndNote records.5 The template for the relevant reference type (such as journal article  or book) determines how the data display in a record. 

    Having provided this background about EndNote, we now discuss two of its   capabilities for using citing/cited data. 

    

Storing and displaying cited and citing reference lists
    Recall that a cited reference list consists of references that the   document cites. A citing reference list, by contrast, is a list of items that   cite the document. EndNote allows one to store and view both types of list within   EndNote records.    One easy way to do so is manually to copy and paste such lists directly from a  bibliographic database or electronic journal into an EndNote record. EndNote does  not come with a distinct field for cited or citing reference lists. One can copy  and paste the data into (for example) the Notes field. One can also  create a reference type that includes a field labeled "cited references" and/or  "citing references" and then copy and paste data into that field.6

    If a given reference list is already very long, the user may decide that it clutters the  EndNote record by taking up too much space.7 There are some easy  remedies for this. Rather than put the data for the list into a field of the EndNote record,  one can put the data into a word processor file. Then, using the link feature that EndNote  provides, one can link from the record to the data. Or, one can create a second EndNote  library containing cited or citing references and then in the same way link to it. However,  one has to use the URL field, since the link feature is available only for this  field. 

    These methods allow one to link from several EndNote records to one word processor file or  EndNote library if one wants to "cache," all in one place, cited or citing reference lists  for a group of documents. In this way, a research group can maintain a single list of  articles cited in the papers it publishes or, in turn, a list of references for documents  that cite its papers. Doing so can be part of the continuing effort of the group to record  all the background literature relevant to its current work as well as to the writing of  future papers. An individual writer might also find the same capabilities useful. 

    To summarize, one can copy and paste reference lists into EndNote records or link  from the records to another file or library containing the lists. Either procedure  can become very tedious if one's library contains a large number of records. It  would help if cited or citing reference lists could be imported in the same way  other data elements (such as author, title, abstract, etc.) are automatically  imported by EndNote import filters. 

    We tested the latter approach by using the EndNote filter for the OCLC version of  PsycINFO. The filter was the latest version, downloaded from the EndNote web site.   Using this filter, cited reference lists were imported into the Notes  field. We modified this filter so that it would import cited reference lists into  a Cited References field,8 which we added by  editing the journal reference type.6 Having made these  two changes, the cited reference lists were now drawn into the field labeled  Cited References. However, the cited reference list wrapped, making it  difficult to read the data. 

    The example just discussed involves PsycINFO. Consider now ISI-produced data.  Persons  wanting to display cited reference lists from ISI Science Citation Index records, for  example, will need to make changes accordingly if they want to import cited reference lists  into a filed specially designed to store and display them. 

    We have talked about how to make reference lists display in records. We turn now to how those  lists can display in library windows. Recall that after one opens an EndNote library,  authors, dates, and titles are displayed by default in the library window. One can change the  fields that display there. For example, one can display data from the fields that contain  cited and citing references lists. Doing so has only limited value, however. There is only  one row of the window for each record, and so there is not enough space for much data from  the cited or citing reference lists for a given record to appear. 

    

Retrieving cited and citing data
    Using EndNote's search engine, one can specify an author and then find all the  documents in the database that cite the author. This would be a way for an author quickly to   bring up records for all the papers that cite him or her  -- that is, to bring up a citing reference list. The procedure for doing this is  easy. After opening the search engine (available off the References  menu), one then uses a drag down menu to specify the field over which to search  for the author's name. If the cited reference list appears in the Notes  field, one should search over the Notes field. If one has created a  special field for the cited reference list, one should search over that  field.9 One can narrow the search by introducing not  only the author's name, but additional information such as a publication date, that  identifies a specific paper by that author. To do this, use the Boolean operator  "and" on the EndNote search engine.     One can also do searches over whatever field contains citing reference lists. This will bring  up records for example that an author (or a specific paper by an author) happens to cite --  that is, it brings up a cited reference list. This would be a way to generate a list of  articles cited in the work of one's favorite author. 

    

How RefWorks Handles Citing/Cited Data
    Whereas EndNote is downloaded to one's hard drive, RefWorks is used in a web  environment. Like EndNote, RefWorks enables one to store, within records,  bibliographic and other information about documents. These records are held within  "folders," which are comparable to EndNote libraries. The title, authors, and  source data for journal records appear in a window that comes up when a folder is  opened. Clicking on the link labeled View enables one to see the full  record. One can manually input data into the records that comprise a folder or one  can use an "import filter" to draw data into the records from databases.     Having provided this background about RefWorks, we turn to its capabilities with  respect to using citing/cited data.10

    

Storing and displaying cited and citing reference lists
    RefWorks allows users to put cited and citing reference lists into RefWorks  records. One way to do so is manually to copy and paste cited and citing reference  lists from a bibliographic database and then paste the data into a RefWorks record.   While RefWorks does not come with a distinct field for cited or citing reference  lists, five fields are available for users to insert data of any kind. A  Notes field is also available.    Cited reference lists can also be imported in the same way other data elements  (such as author, title, abstract, etc.) are automatically imported by RefWorks  import filters. However, the current import filter labeled "CAS SciFinder"  imported the cited reference list from SciFinder Scholar 2001 into the "Tertiary  Title" field.11 For the OCLC version of PsycINFO, the  cited reference list was imported into the Notes field. In both cases the  data in the lists "wrapped" and therefore it was not easy to read.

    Should the user decide that the cited reference list clutters a RefWorks record by taking up  too much space, one can create a web page that caches the data and link to it. One can also  link out from several RefWorks records to one web page, should one want to "cache" the cited  or citing references for a group of documents all in one place. 

    

Retrieving cited and citing data
    RefWorks comes with "Quick" and "Advanced" search engines. Quick Search enables  one to search all fields. Using it, one can therefore search on an author to find  references that cite, or are cited by, the author. Search results are relevancy  ranked. The Advanced Search feature enables one to select from a variety of fields  to search. However, these fields do not include the Notes field or the  five user-defined fields. Therefore, Quick Search is the only way to retrieve  cited/citing lists if they appear in the Notes filed or the five  user-defined fields.     

Citation Managers: Suggested Enhancements
    While EndNote and RefWorks provide ways to work with cited/citing data, their capabilities in  this respect can be expanded. The following are suggested enhancements that can be  incorporated not only into these two packages, but any citation managers in which they are  lacking.     First, a field for cited/citing reference lists could be introduced in record type  templates. Vendors could also provide filters that facilitate importing of  reference lists in the non-wrapping, itemized format of the original. As it stands  now, recall that to import the citation data and display it in a field labeled  citations, EndNote's user must edit the import filter as well as the record type  template. Users may be reluctant to make these changes. RefWorks (on our trial  version) does not allow users to edit filters. 

    Second, it would be useful if references that appear in a record's cited or citing reference  fields were hyperlinked to their corresponding records. Such hyperlinking would assist the  user in exploiting citing/cited relationships between documents. For example, it would enable  one to bring up an abstract or notes about one document and then immediately go to the  abstract or notes for a citing or cited document. Also, given that one can link to the full  text of a document from its corresponding record, such hyperlinking creates a network of  linkages between the full text of citing and cited documents. Finally, by enabling the user  to create a one-to-one correspondence between records and physical files containing  offprints12, citation managers enable one to locate the hard  copy of documents in one's filing system. The aforementioned hyperlinking would enable one  quickly to retrieve the hard copies of citing and cited documents.13

    Third, software could also perform the following function. At the user's discretion, when a  record "x" is saved, the software would spawn independent records for the items in its citing  and cited reference lists. This would obviate the need independently to create records for  those references. An intermediate screen could be provided that would enable the user to  designate which items in a cited or citing reference list should be spawned. 

    Finally, in addition to the current summary list of records provided by EndNote and  RefWorks (available when one opens a library or folder, respectively), it would be  helpful to have a second view in which the citing/cited relationships between  documents are displayed. For example, a document could be identified by author and  date in a center column. A left-hand column would list citing documents while a  right-hand column would list the cited references. So that the data do not  become excessively long in that view, a hyperlink to an intermediate screen could  be provided that would list the citing references, and another hyperlink would be  provided for the cited references. 

    

The Role of Publishers
    We have discussed enhancements to citation managers that would improve their  capabilities with respect to citing and cited reference lists. We now shift  attention to the publisher interfaces from which users download data into citation  managers. To begin with, consider electronic journals. These can be enhanced to  make it easier to "harvest" citing and cited reference lists.     For example, Science provides a link to "other online articles" that  cite the article one is viewing (what we have called a citing reference list).   Also, it enables one to download reference data for the article one is viewing to a  citation manager. However, it does not enable one to download directly to a  citation manager the citing reference list or the list of references that the  article itself cites. Nature provides links to both "ISI articles  that reference this article" and "ISI related articles." However, it too does not  provide a way to download this data, nor the references the article itself cites,  into citation managers. Again, Applied Physics Letters identifies  "citing articles" but does not provide an interface to download them into a  citation manager. 

    Bibliographic database interfaces can also be enhanced to make it easier to download citing  and cited reference lists into citation managers. Ideally, they would all enable direct  downloading of citing and cited reference lists, when available, plus they would offer the  ability to download to a variety of citation management software. With respect to its Web of  Science product, ISI supports only direct export into EndNote, Reference Manager, and  ProCite. SciFinder Scholar enables one to bring up a list of cited references or a list of  citing ones. It would be helpful at that point to have a link so that one can directly  download the search results in citation managers. MathSciNet similarly makes citing and cited  reference lists available but also does not provide a direct downloading capability into  citation managers. OCLC First Search, at least on PsycINFO, provides an export feature, but  only enables downloading with it to EndNote, not other citation managers as well. 

    In short, publishers of electronic journals and bibliographic databases can do more  to facilitate use of citation managers with respect to citing and cited reference  lists. Industry-wide standards might help encourage greater cooperation between  publishers and producers of citation management software. We have not explored what  standards in this realm have been discussed or defined. Suffice it to say that   standardization in data presentation might make it easier to create import filters or   direct importing mechanisms, for drawing search results into citation managers from a   variety of electronic journals and bibliographic databases.  Standardization may also   make it unnecessary for publishers to provide separate export links for each of the citation  managers on the market.  Examples of standardization that could help in this context  include: which bibliographic data elements (e.g., author, title, journal title, etc.) to  include in citing and cited reference lists; how those data elements should appear (e.g.,  whether to abbreviate journal names); and what tags to use for citing and cited reference  lists.

    

Conclusion
    At the outset, we discussed how an increasing number of library resources enable  identification not only of documents relevant to one's research, but also other  documents that cite those documents. If our analysis of two citation managers is  any indication, citation management software can do more to keep pace with this  emerging trend. Also, publishers can explore more ways to facilitate the use of  citation managers with respect to the citing and cited reference lists that they  provide. Increased cooperation between citation manager producers and publishers  will enable researchers to better exploit the valuable research tool that  citing/cited relationships afford.14    

Notes
    1 Our focus is on the widely-used EndNote  software, as well as another citation citation manager that has been  attracting attention, RefWorks.    2 The term "reference lists" is used in MathSciNet  documentation. MathSciNet uses this term to mean what we call "cited reference  lists." Note that what MathSciNet calls "reference citations" are the same as what  we call "citing reference lists."

    3 According to CAS customer service, this {information}  about the coverage of CA/CAPlus pertains to SciFinder Scholar.  Re.  MathSciNet, see {http://e-math.ams.org/msnhtml/whats_new.html}.

    4 The paper "EndNote at Lehigh"   describes how this software has been implemented at Lehigh. What follows is based  on EndNote 5, specifically 5.0.2. EndNote 6 was recently released, but does not  expand the functionality of EndNote 5 with respect to capabilities for handling  citing/cited data. 

    5 See the following for an explanation of these: {http://www.endnote.com/support/helpdocs/Importing5.pdf} {http://www.endnote.com/support/helpdocs/Search_Remote5.pdf}

    6 To add fields for "Cited References" and "Citing  References" to a reference type -- e.g., journal articles-first choose  Preference from the Edit menu in EndNote. A window labeled  "EndNote Preferences" then shows up. Highlight Reference Types in the  left column and click the button Modify Reference Types. Another window  labeled "Edit Reference Types" shows up. Under the column for Journal  Articles, add "Cited References" in the row labeled "Custom 1," and "Citing  References" in the row labeled "Custom 2," respectively. Click the button labeled  OK. It is necessary to do this for any record type for which one wants to  store citing or cited references. This is because the generic template for record  type display does not include fields for either cited or citing references. Since  the available fields for any record type are drawn from those on the generic  template, these fields will not be in any of the record types. 

    7 The problem here would almost always be cosmetic,   not one having to do with limitations on the capacity of any given field to hold   data: "the Notes and Abstract fields, like all other fields, can hold up to   32,000 characters which is equivalent to about 8 pages of single-spaced text."   EndNote 5 manual, page 79.

    8 To modify the PsycINFO filter so that it will draw in  cited reference lists, first choose Import Filters/Open Filter Manager...  from the File menu. Highlight the OCLC PsycINFO filter and click the  button Edit. A window labeled with the filter name shows up. Highlight  Template in the left column, select Journal Articles in the combo  box labeled Reference Type, and add a new row for "Cited Reference:" and  "Cited References:" under the columns labeled Tag and Field(s),  respectively. You may save this modified filter by choosing Save As... in  the File menu. 

    9 Note that if the user creates a new EndNote field   labeled (e.g.) "cited references" for Custom 1, the search engine menu options   listing the searchable fields will not call it such. Rather, it still uses the   label Custom 1.

    10 We relied on a trial version of RefWorks in doing   our analysis.

    11 The assumption here is that the "CAS SciFinder"   filter can be used for SciFinder Scholar 2001 records. RefWorks indicated that the   references should not go to the tertiary title field and that they can fix this.

    12 For example, one of us does this by labeling with   numbers file folders containing offprints, and then cross-referencing those numbers in the   "label" field of corresponding EndNote records.

    13 The citation manager Biblioscape has a feature very  similar to the afore-mentioned hyperlinking capability. It enables one to add  cited reference links to a reference and then go to those linked references by clicking.   The cited links can be chosen as "bi-directional links" so that the  original reference will automatically become a cross link, in turn, for the linked  references. In Biblioscape, this "bi-directional link" relationship is described  in the terms "cited"/ "is cited," which corresponds to what we refer to as a  "cited/citing" relationship. It does not provide hyperlinks directly out of the  reference itself; one must open the reference and then go to the crosslink tab to  display the cited references.

    14 We wish to acknowledge the assistance of Christine Capen at RefWorks for answering questions about this software and for helpful observations and comments, as well as personnel at Biblioscape, EndNote, and ISI for clarifications about their software, as well as the CAS help desk for information related to SciFinder Scholar. Thanks also to Sharon Siegler for pointing out and discussing some of the resources that appear on {http://www.lehigh.edu/library/footnote/} 

    

References
    ISI ResearchSoft. 1988-2001.  EndNote 5 manual. Berkeley, CA: ISI ResearchSoft.    Siegler, Sharon, and Simboli, Brian.  2002. EndNote at Lehigh.  Issues in Science & Technology  Librarianship 34 (Spring, 2002). [Online]. Available   http://www.istl.org/02-spring/article4.html [August 5, 2002].

    

  

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