ad:ExternalReference.informationSystemName
http://inspire.ec.europa.eu/ont/bu-base#ExternalReference.informationSystemName
rdfs:comment
http://www.w3.org/2000/01/rdf-schema#comment
EXAMPLES: Danish Register of Dwellings, Spanish Cadastre.
@en
graph:default
https://triplydb.com/inspire/bu-base/graphs/default