CrossRef
CrossRef is on of the DOI registration agencies, responsible for scholarly and professional publications; with more than 2000 publishers participating. The participating publishers register metadata records for each each DOI and thereby built a big multidisciplinary reference database with more than 29 million records.
The most usage scenarios described below require that the institution become an CrossRef affiliate, e.g. by signing the
- library agreement, see http://www.crossref.org/03libraries/index.html
Conditions: There is no charge for most libraries to get a CrossRef account to retrieve DOIs or metadata, but there is a fee for high-volume (> 1 million) requests - affiliate agreement, see http://www.crossref.org/04intermediaries/index.html
Conditions: annual fee according to price list.
The MPG is a CrossRef affiliate, more information is available via Inga.
Fetching Metadata[edit]
CrossRef supports several methods to request the metadata from its reference database:
via the OpenURL interface[edit]
The OpenURL interface provides an convenient way to access the metadata record for a known DOI. The service supports requests in compliance with version 0.1 or version 1.0 of the OpenURL standard. Currently no user account is required to access this interface, but this is subject to change.
Example requests:
- article, crossref_query output: http://www.crossref.org/openurl?url_ver=Z39.88-2004&req_dat=usr:pwd&rft_id=info:doi/10.1103/PhysRev.47.777&redirect=false
- article, unixref output: http://www.crossref.org/openurl?url_ver=Z39.88-2004&req_dat=usr:pwd&rft_id=info:doi/10.1103/PhysRev.47.777&format=unixref&redirect=false
- book chapter, crossref_query output: http://www.crossref.org/openurl?url_ver=Z39.88-2004&req_dat=usr:pwd&rft_id=info:doi/10.1007%2F978-3-540-73859-6_29&redirect=false
- book chapter, unixref output: http://www.crossref.org/openurl?url_ver=Z39.88-2004&req_dat=usr:pwd&rft_id=info:doi/10.1007%2F978-3-540-73859-6_29&format=unixref&redirect=false
More information: http://www.crossref.org/openurl_info.html
via the OAI interface[edit]
CrossRef operates an OAI-PMH service provider for distributing metadata to subscribers which is especially helpful for a bulk download of metadata records. Accessing this interface requires an additional agreement which is currently not avilabl
Example requests:
- Identify: http://oai.crossref.org/OAIHandler/?verb=Identify
- Record (login required): http://oai.crossref.org/OAIHandler/?verb=GetRecord&metadataPrefix=cr_unixml&identifier=info:doi/10.1038/42304
More information: http://www.crossref.org/webservices.html
Available Outputs[edit]
- crossref_query output: includes a minimal set of metadata, e.g. only the first author name.
Schema: http://www.crossref.org/qrschema/crossref_query_output2.0.xsd - unixref output: a more verbose XML response, e.g. complete author information.
Schema: http://www.crossref.org/schema/unixref1.0.xsd
Additional Tools[edit]
doi resolver (provide a doi and be redirected to the corresponding article location): http://dx.doi.org
free doi lookup (provide metadata and receive the corresponding doi): http://www.crossref.org/guestquery/
Crossref simple text query (provide a reference): http://www.crossref.org/SimpleTextQuery/
Further Reading[edit]
- CrossRef back-office: http://doi.crossref.org/servlet/useragent?func=showHome
- CrossRef Documentation: http://doi.crossref.org/doc/userdoc.html (login required)
- Overview on affiliate fees: http://www.crossref.org/04intermediaries/34affiliate_fees.html
- Usage of CrossRef framework by MPG/SFX: https://dev.livingreviews.org/projects/vlib/wiki/SFXDOI