query: SELECT ?item ?inv ?url1 ?url2 WHERE {
    ?item wdt:P31 wd:Q3305213 .
    ?item p:P217 ?invstatement .
    ?invstatement ps:P217 ?inv .
    ?invstatement pq:P195 wd:Q2051997 .
    OPTIONAL { ?item wdt:P973 ?url1 . FILTER regex(str(?url1), "^.+tate.+$") } .
    OPTIONAL { ?item wdt:P973 ?url2 . FILTER regex(str(?url2), "^.+nationalgalleries.+$") } .
    MINUS { ?item wdt:P195  wd:Q430682 .
             ?item p:P217 ?invstatement2 .
             ?invstatement2 ps:P217 ?inv .
    		?invstatement2 pq:P195 wd:Q430682 .
          }
    FILTER regex(?inv, "^AR\\d+$") 
    } LIMIT 101