query: #title: Unreferenced Wikimedia username statements
  # 2021-09-26: 1020 results
  SELECT ?n ?itemLabel WHERE {
    ?item p:P4174 ?n .
    MINUS { ?n prov:wasDerivedFrom ?ref . }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }