Here we publish the bibliographic data of the electronic documents - mostly books - in the Hungarian Electronic Library in the form of Linked Open Data. The dataset contains external references to dictionaries and namespaces such as: VIAF, BIBO, GeoNames, SPAR Ontologies, DCMI Type Vocabulary, LCSH and the SKOS implementation of the National Széchényi Library's thesaurus. The metadata can be downloaded in RDF format as a single ZIP package or as separate files, or can be retrieved from the web server through "content negotiation", or searchable in a Virtuoso database with SPARQL language queries. Here is a presentation (in Hungarian) about the semantic web developments of MEK and DKA. More information can be obtained at info@mek.oszk.hu.

Dataset characteristics

(Last updated: June 27, 2019.)
  • Number of documents: 19.067
  • Number of triplets: 1.252.307
  • Number of links to certain external namespaces and dictionaries:
       viaf.org: 14.769
       loc.gov: 82.709
       nektar.oszk.hu: 71.053
       geonames.org: 9.305
       sparontologies.net: 61.410
       purl.org/dc/dcmitype: 19.077
       purl.org/ontology/bibo: 19.077
  • Namespaces and dictionaries
    used for references

    SPARQL Endpoint
    (Virtuoso database)


    https://v.mek.oszk.hu/sparql


    Default Data Set Name:
    http://localhost:8890/DAV/DKAVAD/

    SPARQL query example
    Dramas, plays published under a Creative Commons license
    PREFIX rdf: 
    PREFIX rdfs: 
    PREFIX bibo: 
    PREFIX dcterms: 
    SELECT distinct ?title ?x ?r
    WHERE { ?x dcterms:type "plays" .
    ?x dcterms:title ?title .
    ?x dcterms:rights ?r .
    FILTER regex(str(?r), "https://creativecommons.org/licenses")
    }
    

    Sample record

    Content negotiation
    (retrieving RDF metadata from the nginx
    webserver via HTTP protocol)


    Example:
    curl -i https://mek.oszk.hu/data/16000/16078 -H "Accept: application/rdf+xml"
    
    HTTP/1.1 303 See Other
    Server: nginx
    Date: Mon, 05 Jan 2015 13:59:19 GMT
    Content-Type: text/html
    Content-Length: 162
    Location: https://mek.oszk.hu/16000/16078/metadata.rdf
    Connection: keep-alive
    Keep-Alive: timeout=5
    

                        CC0