query: SELECT DISTINCT ?item ?itemLabel ?dacs ?adagp ?citizen ?citizenLabel WHERE {
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],nl". } 
    ?item wdt:P3901 ?adagp.
    FILTER NOT EXISTS{ ?item wdt:P4663 ?dacs. }
    OPTIONAL { ?item wdt:P27 ?citizen. }
  }