1. DOI & Crossref Arnoud de Kemp Springer-Verlag dekemp@springer.de

2. www.crossref.org Not-for-profit network founded early 2000 First full-scale implementation of DOI PILA: Publishers Independent Linking Association, Inc. 168 publishers/societies 60 libraries 29 intermediaries

3. What CrossRef is not: A product for sale An article database A direct-to-end-user service A search interface A broker of full-text content A consortium of big commercial publishers CrossRef: complete citation linking backbone for all scholarly literature online (new as well as old)

4. For Whom? Any publisher of primary research material in digital form Libraries for localized linking solutions, enriching online catalogues and databases with links to their own full-text holdings Secondary publishers and journal hosting services Technology companies

5. Key Benefits No state links: a DOI link is a persistent link in citations and databases A single agreement rather than numerous bilateral linking agreements Newest literature: outbound links to the latest cited sources Higher accessibility through inbound links Central DOI Directory

6. How the System works (A) Join as a member and receive a DOI prefix Create your own DOI (using the prefix) and assign it the article`s metadata and URL Submit the record in a strict XML-based DTD format to the CrossRef MDDB CrossRef registers each article DOI and URL in a central directory, thus allowing for permanent inbound links

7. How the System works (B) In a separate process, the publishers also submits the citations contained in each article to the Reference Resolver, the front- end component of the MDDB The publisher, library, XYZ can add outbound links to any of the article´s citation Special querying and look-up process

8. Why Libraries participate? Library users want to navigate directly from citations or database records to journal articles Library records do not contain article-level information or links CrossRef is a key piece of the puzzle in localized linking solutions for digital collections CrossRef does not compete with OpenURL, which is a syntax for transporting metadata within URLs All CrossRef publishers are OpenURL compliant

9. Some numbers & Other Information 1,2 million resolutions in April 2002 Deposits for over 5 million articles Backfile content is being added, e.g. APS goes back to 1893 Solution for the „appropriate copy problem“ Linking to non-journal content, beginning with conference proceedings and books

10. Some Cooperations International DOI Foundation (IDF) Corporation for National Research Initiatives (CNRS): Handle System Ex Libris OhioLINK Los Alamos National Laboratory Board of Directors representing many parties