query: #title: Only one of the two items can have P31 = [[d:Q21286738|Wikimedia permanent duplicate item <small>(Q21286738)</small>]]
  # Complex constraint from [[Property talk:P2959]]
  # FIXME: Remove P31=Q21286738 from one of the items or remove P2959
  SELECT DISTINCT ?item #?itemLabel ?itemDescription ?value ?valueLabel ?valueDescription
  {
  	?item wdt:P2959 ?value .
    	?item wdt:P31 wd:Q21286738 .
    	?value wdt:P31 wd:Q21286738 .
    	FILTER ( ?value != ?item ) .
    	#SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en" } .
  }
  ORDER BY ASC(xsd:integer(STRAFTER(str(?value), "Q")))