NFDI4Culture provides a Knowledge Graph of aggregated cultural objects. Its SPARQL API can be used to query - [list of databases](https://nfdi4culture.de/resources/knowledge-graph.html#query=PREFIX%20rdf%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0APREFIX%20rdfs%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0APREFIX%20schema%3A%20%3Chttp%3A%2F%2Fschema.org%2F%3E%0APREFIX%20nfdico%3A%20%3Chttps%3A%2F%2Fnfdi4culture.de%2Fontology%23%3E%0ASELECT%20*%20WHERE%20%7B%0A%20%20%20%3Fx%20%3Fp%20%3Fo%20.%0A%20%20%3Fx%20a%20schema%3ADataCatalog%20.%0A%7D&endpoint=https%3A%2F%2Fnfdi4culture.de%2Fsparql&requestMethod=POST&tabTitle=Query%201&headers=%7B%7D&contentTypeConstruct=application%2Fn-triples%2C*%2F*%3Bq%3D0.9&contentTypeSelect=application%2Fsparql-results%2Bjson%2C*%2F*%3Bq%3D0.9&outputFormat=table) - [documents indexed with a subject](https://nfdi4culture.de/resources/knowledge-graph.html#query=PREFIX%20schema%3A%20%3Chttp%3A%2F%2Fschema.org%2F%3E%0ASELECT%20DISTINCT%20%3Fitem%20%7B%0A%09%3Fitem%20schema%3Akeywords%20%3Chttps%3A%2F%2Ficonclass.org%2F11G183%3E.%20%0A%7D&endpoint=https%3A%2F%2Fnfdi4culture.de%2Fsparql&requestMethod=POST&tabTitle=Query%204&headers=%7B%7D&contentTypeConstruct=application%2Fn-triples%2C*%2F*%3Bq%3D0.9&contentTypeSelect=application%2Fsparql-results%2Bjson%2C*%2F*%3Bq%3D0.9&outputFormat=table) - [subjects of a document](https://nfdi4culture.de/resources/knowledge-graph.html#query=PREFIX%20schema%3A%20%3Chttp%3A%2F%2Fschema.org%2F%3E%0ASELECT%20DISTINCT%20%3Fsubject%20%7B%0A%09%3Chttps%3A%2F%2Fcorpusvitrearum.de%2Fid%2FF14968%3E%20schema%3Akeywords%20%3Fsubject.%20%0A%7D&endpoint=https%3A%2F%2Fnfdi4culture.de%2Fsparql&requestMethod=POST&tabTitle=Query%204&headers=%7B%7D&contentTypeConstruct=application%2Fn-triples%2C*%2F*%3Bq%3D0.9&contentTypeSelect=application%2Fsparql-results%2Bjson%2C*%2F*%3Bq%3D0.9&outputFormat=table) - [vocabularies and number of subjects](https://nfdi4culture.de/resources/knowledge-graph.html#query=PREFIX%20schema%3A%20%3Chttp%3A%2F%2Fschema.org%2F%3E%0ASELECT%20%3Fvoc%20(COUNT%20(%3Fsubject)%20AS%20%3Fcount)%20%0AWHERE%20%7B%0A%20%20%3Fsubject%20schema%3AinDefinedTermSet%20%3Fvoc%0A%7D%20GROUP%20BY%20%3Fvoc&endpoint=https%3A%2F%2Fnfdi4culture.de%2Fsparql&requestMethod=POST&tabTitle=Query%204&headers=%7B%7D&contentTypeConstruct=application%2Fn-triples%2C*%2F*%3Bq%3D0.9&contentTypeSelect=application%2Fsparql-results%2Bjson%2C*%2F*%3Bq%3D0.9&outputFormat=table) - ... co-occurrences are possible too. Contact: Lozana Rossenova