query: SELECT ?film ?filmLabel ?seriesLabel ?durationLabel 
  WHERE {?film wdt:P57 wd:Q2071 .
         OPTIONAL {?film wdt:P2047 ?duration .
                   }
         OPTIONAL {?film wdt:P179 ?series .
                   }
         # get a label in English
        SERVICE wikibase:label {
              bd:serviceParam wikibase:language "en, pl, it, fr" .
          }
         }
  ORDER BY ?duration