query: #title: In the Museum without a link
  # Complex constraint from [[Property talk:P4673]]
  # Items that have [[Property:P195|collection&#32;<small dir="ltr">(P195)</small>]] -> [[d:Q1565911|Museum of Fine Arts, Houston <small>(Q1565911)</small>]], but that don't have a [[Property:P4673|Museum of Fine Arts, Houston object ID&#32;<small dir="ltr">(P4673)</small>]] link
  SELECT DISTINCT ?item ?url WHERE {
    ?item wdt:P195 wd:Q1565911 .
    OPTIONAL { ?item wdt:P973 ?url } . 
    MINUS { ?item wdt:P4673 [] } .
  }  LIMIT 500