The network of links to and from scholarly publications continues to grow rapidly. The Publishers International Linking Association (PILA) has announced that its CrossRef service (http://www.crossref.org) will open access to its collection of Digital Object Identifier (DOI) article links to secondary publishers at the end of this month. Chemical Abstracts Service (CAS; http://www.cas.org) will link records from its Chemical Abstracts database and full text holdings to citations within electronic journals on five major publishers' Web sites. DataStar, a division of Thomson's Dialog Corp. (http://www.dialog.com/info/products/datastar-index.shtml), now offers e-links from major scientific and technical abstract databases on its system to publishers' full-text journals.
The CrossRef program, initiated by scholarly publishers in November 1999, continues to grow rapidly. At present it has 44 members, 60 percent of them not-for-profit publishers, according to Ed Pentz, executive director of PILA. CrossRef has DOI tags and metadata for some 1.7 million articles from 2,800 journals and expects to reach 3 million articles by the end of the year.
At the end this month, CrossRef will open access to its DOIs to secondary publishers of abstracting-and-indexing services. The program will work on a one-way basis, allowing the publishers to add DOI data to individual records in their abstracting-and-indexing services. Although traditional online services won't have access to the DOIs at present, Pentz didn't seem averse to dealing with them. Even without access, the host search services might see CrossRef's DOIs appearing on their service, if only through the altered records from secondary publishers that do use CrossRef. Pentz indicated that he hoped to offer two-way service and make the index or abstract records equally available to full-text publishers in the future. Since many of PILA's members are secondary as well as primary publishers, that development would seem likely.
Pentz clearly plans to expand CrossRef in all directions. The service has an active program to increase the number of member publishers, and it will next extend the DOI tagging beyond journal articles to conference proceedings, then encyclopedias and reference sources, and then books. Pentz seemed to have no hesitation in expanding access to any source or format of digital data as long as the source was peer-reviewed or in some way proven reliable.
Already PILA has expanded its coverage outside the scientific/technical arena to social science journals. It now handles articles from MIT Press, the University of Chicago Press, and Cambridge University Press, and is in discussion with Sage. We asked Pentz if he could foresee linking to non-journal material such as government documents or even newspaper articles—citations common in social science scholarship. He said PILA was already having conversations with some government agencies.
Pentz indicated that CrossRef could even deal with services that don't use DOIs for identifiers, though he considered DOI to be the best solution to the problem of stabilizing and archiving Web-accessible scholarship.
CAS has started its own program to link to full-text sources. Since 1997, the company and its partners have extended access to full-text sources through its ChemPort Connection to sci-tech journals from 90 publishers. The new linkings reach publications from five of the 90—Academic Press/IDEAL; the American Institute of Physics; the Royal Society of Chemistry; Springer-Verlag; and the American Chemical Society (ACS), which also owns CAS. These publishers will receive the reference links for free.
Once in place, readers of the electronic versions of the journal articles on a participating publisher's Web site will be able to click from a footnote citation to articles from any other ChemPort publisher, other articles citing the article referenced, and to CAS databases. (For a look at how the new reference linking works, go to the American Chemical Society's site for a demo of its "hot article" service at http://pubs.acs.org/hotartcl/index.html.) The system will support both subscription access and credit-card pay-per-view payments. In 2001, CAS and its STN International partner expect to expand the service to all ChemPort publishers, and will work to extend this reference-linking service to other secondary databases on the system.
CAS produces the world's largest database of chemical information, with over 19 million abstracts to chemistry-related literature and patents and 25 million substance records. STN International, the leading sci-tech online search service, is a network of databases from CAS, FIZ Karlsruhe in Germany, and the Japan Science and Technology Corp.
DataStar, the European section of Thomson's Dialog Corp., has announced new e-Journal Links for its pharmaceutical and scientific abstract databases. Users who subscribe to publishers' electronic journals can register with DataStar and, when they search bibliographic databases such as MEDLINE or BIOSIS on DataStarWeb, link directly from appropriate DataStar results to the full-text on the publisher's Web sites. Dialog/DataStar customizes the user's site to reflect the subscription-approved journals, after which a logo will appear at the top of any abstract record display when the journal title matches the user's access. The e-journal article will usually appear in PDF format, or occasionally in HTML, in a separate browser window.
According to DataStar, the number of bibliographic databases affected depends on the number of files containing records from partner publishers or aggregators. DataStar can create links to as many databases as necessary, and plans to increase the number of databases offering the feature as the number and range of partners in the program increase. At present the publishers and aggregators participating in the e-Journal Link program are the American Institute of Physics (AIP), HighWire Press, CatchWord, Academic Press/IDEAL, Karger, SwetsNet, Information Quest, SIAM, and Springer-Verlag. As new publishers and aggregators enter the system, DataStar will send "splash screen" notices to users.
With both the CAS ChemPort Connection and DataStarWeb services, users must already subscribe to the electronic versions of the journals for the links to work. Some publishers may offer pay-per-view access, but not necessarily all.
The day when a user can move seamlessly through the world of scholarly publishing—using an abstract to reach a document or a document to reach an abstract or a footnote to reach full text with no effort or barrier—is still far away. But it's getting closer.