query: SELECT ?item ?itemLabel ?itemDescription (GROUP_CONCAT(DISTINCT ?oaname; separator=", ") as ?oa)
  {
      ?season wdt:P3450 ?item .
      ?item wdt:P17 wd:Q145 .
      OPTIONAL { ?item wdt:P2541 ?oa . ?oa rdfs:label ?oaname. FILTER(lang(?oaname)="en") }
      SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }  
  GROUP BY ?item ?itemLabel ?itemDescription