query: SELECT ?item ?release ?nr_e (GROUP_CONCAT(DISTINCT(?enlabel)) as ?enlabels) WHERE 
  {  
    ?item wdt:P31 wd:Q21191270 .
    ?item wdt:P179 wd:Q1002254 .  
    ?item p:P179 ?episode_statement .
    ?episode_statement pq:P1545 ?nr_e  .
    ?item wdt:P577 ?release . 
    ?item rdfs:label ?enlabel . 
    FILTER(lang(?enlabel)="en") 
  } GROUP BY ?item ?release ?nr_e ORDER BY xsd:integer(?nr_e) ?release