query: #title: In the museum without a link
  # Complex constraint from [[Property talk:P4737]]
  # Items that have [[Property:P195|collection&#32;<small dir="ltr">(P195)</small>]] → [[d:Q201469|Solomon R. Guggenheim Museum <small>(Q201469)</small>]], but that don't have a [[Property:P4737|Solomon R. Guggenheim Foundation artwork ID&#32;<small dir="ltr">(P4737)</small>]] link
  SELECT DISTINCT ?item ?url WHERE {
    ?item wdt:P195 wd:Q201469 .
    OPTIONAL { ?item wdt:P973 ?url } . 
    MINUS { ?item wdt:P4737 [] } .
  }  LIMIT 500