query: #Makers with works in collection of museums whose work is represented by Pictoright who have died less than 70 years ago or are still alive
  SELECT ?maker ?makerLabel ?born ?died WHERE {
    ?maker wdt:P31 wd:Q5 .              # human
    ?maker wdt:P6379 wd:Q679527 .       # has works in collection: Boijmans van Beuningen
    ?maker wdt:P6275 wd:Q71528227 .     # copyright representative = CISAC
  OPTIONAL {
    ?maker wdt:P569 ?born .             # date of birth
    }
  
  BIND(NOW() AS ?date)
  FILTER (?born >= "1800-01-01T00:00:00Z"^^xsd:dateTime)
  OPTIONAL { ?maker wdt:P570 ?died. }
  FILTER(!BOUND(?died) || ?date < ?died || ?died >= "1949-01-01T00:00:00Z"^^xsd:dateTime) # alive or dead less than 70 years ago
  
  SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],nl,en".} 
  }
  
  GROUP BY ?maker ?makerLabel ?born ?died ?copyrightrep
  ORDER BY ASC(?born)