query: # "Battles of the Middle Ages" without place or date
  SELECT DISTINCT ?item ?itemLabel ?placeLabel ?date ?coords WHERE {
    ?item wdt:P31 wd:Q15991159 .
    
    { 
      FILTER NOT EXISTS { ?item wdt:P276 ?place . }
    } UNION {
      FILTER NOT EXISTS { ?item wdt:P585 ?date . }
    }
    OPTIONAL{ ?item wdt:P625 ?coords . }
    
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en,fr" }
  } ORDER BY ?itemLabel