query: SELECT ?item ?itemLabel ?url WHERE {
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],nl,en". }
    ?item wdt:P31 wd:Q3305213.
    ?item wdt:P195 wd:Q924335.
    OPTIONAL { ?item wdt:P973 ?url. }
  }
  LIMIT 1000