query: SELECT ?item (COUNT(DISTINCT ?painting) AS ?count) WHERE {
    ?painting wdt:P31 wd:Q3305213 .
    ?painting wdt:P195 ?item .
     ?painting p:P528 ?catalogstatement .
    ?catalogstatement ps:P528 ?catalogid . 
    ?catalogstatement pq:P972 ?catalog .
    ?catalog wdt:P50  wd:Q757837 . 
    } GROUP BY ?item
  ORDER BY DESC(?count)