query: SELECT	?item ?itemLabel ?subject ?subjectLabel ?vol ?coa
  WHERE
  {
  	?item	wdt:P1433 wd:Q665807 .
    	?item	wdt:P31 wd:Q13433827 .
    	OPTIONAL { ?item wdt:P921 ?subject 
    	  	  	OPTIONAL {?subject wdt:P94 ?coa }
    	  	  }
    	OPTIONAL {?item wdt:P478 ?vol }
    	SERVICE wikibase:label { bd:serviceParam wikibase:language "en" }
  }
  ORDER BY ?itemLabel ?item