SRU interface

CERL members and other interested institutions may make use of the CERL Thesaurus in their own database environment as:

  • a supporting tool for automated query expansion, similar to the Assisted Searching functionality as provided in the Heritage of the Printed Book database.
  • a source of reference for imprint and printing place names as well as names of other persons and corporate bodies from the hand press era, including links to images of printers’ devices and other electronic resources.
  • an access point to provenance information hidden in library catalogues throughout Europe.
  • or any other yet unconsidered purpose.

For this purposes the CERL Thesaurus can be accessed by a remote software application (e.g. a database system) via the Search and Retrieve URL (SRU) protocol.

The CERL Thesaurus SRU interface currently supports the protocol version 1.2 and is available from https://data.cerl.org/thesaurus/_sru. Please see the Explain record for details on the available indexes.

Records are available in MARCXML and a specific output format for implementations of Assisted Searching. A description of the record structure is available from this document: CTAS Format Description v1.1 – changes to the former CTAS version (CTAS Format Description v1.0) are marked in red.

Please find the full SRU specification on the Library of Congress’ website: http://www.loc.gov/standards/sru/
Please note: The XML encoding follows the MARCXML schema, but the fields used are not MARC21 but those of the
CERL Thesaurus’ internal format

Linked Data

The CERL Thesaurus is also available as Linked Data. The RDF output uses standard vocabulary wherever possible, mainly the RDA Vocabulary (http://rdvocab.info/), but also the Geonames Ontology (http://www.geonames.org/ontology/), the WGS Geo Positioning vocabulary (http://www.w3.org/2003/01/geo/wgs84_pos), the FOAF Relationship vocabulary (http://vocab.org/relationship/), the Vocabulary of the Gemeinsame Normdatei (Documentation) and the Europeana Data Model (EDM) (http://europeana.eu/terms/).

Those elements missing in the above vocabularies are defined by the CERL Thesaurus Vocabulary (http://www.cerl.org/namespaces/ct.xml – see here for a human readable documation (Parrot)).

CERL Thesaurus records are returned in RDF/XML if the HTTP-header Accept is set to application/rdf+xml.

Beacon files that provide a mapping of IDs from external authority files to CERL Thesaurus URIs (see http://meta.wikimedia.org/wiki/Dynamic_links_to_external_resources) are available for the following files: GND (PND): (13.9 MB).

The CERL Thesaurus data is available under the terms of Etalab’s Open Licence, which can be considered equivalent to ODC-BY and CC-BY 2.0. Please see here for the full legal text of the licence in French or English