Querying the OpenCitations Corpus

OpenCitations makes available a SPARQL endpoint for querying the data included in the OpenCitations Corpus. While several queries are possible according to the model described in the website (and, with more details, in the official metadata document of the Corpus), we have received some requests by users of the service for exemplar queries. We have chosen two of them, which are particularly relevant with regard to the work that has been done in the past months by the Initiative for Open Citations – that we have already introduced in another blog post.

Query: return all the papers (including their titles) citing the article with DOI “10.1038/227680a0”.

PREFIX cito: <http://purl.org/spar/cito/>
PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX datacite: <http://purl.org/spar/datacite/>
PREFIX literal: <http://www.essepuntato.it/2010/06/literalreification/>
SELECT ?citing ?title WHERE {
  ?id a datacite:Identifier ;
    datacite:usesIdentifierScheme datacite:doi ;
    literal:hasLiteralValue "10.1038/227680a0" .
  ?br 
    datacite:hasIdentifier ?id ;
    ^cito:cites ?citing .
  ?citing dcterms:title ?title
}

Query: return all the papers cited by the bibliographic resource “br/4186” included in the OCC, including the text of bibliographic references used in “br/4186” for making the citations and the titles of the cited papers.

PREFIX cito: <http://purl.org/spar/cito/>
PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX biro: <http://purl.org/spar/biro/>
PREFIX frbr: <http://purl.org/vocab/frbr/core#>
PREFIX c4o: <http://purl.org/spar/c4o/>
SELECT ?cited ?cited_ref ?title WHERE {
  <https://w3id.org/oc/corpus/br/4186> cito:cites ?cited .
  OPTIONAL { 
    <https://w3id.org/oc/corpus/br/4186> frbr:part ?ref .
    ?ref biro:references ?cited ;
      c4o:hasContent ?cited_ref 
  }
  OPTIONAL { ?cited dcterms:title ?title }
}