query: SELECT DISTINCT ?item ?itemLabel ?RKD_url WHERE {
    ?item wdt:P6379 wd:Q17153751.
    OPTIONAL { ?item wdt:P650 ?RKDid. }
     BIND(IRI(CONCAT('https://rkd.nl/nl/explore/artists/',?RKDid)) AS ?RKD_url)
    MINUS {  ?item wdt:P31 wd:Q5.}
  }