query: SELECT ?item ?itemLabel ?office ?officeLabel
  WHERE { 
    ?item wdt:P31 wd:Q3624078 .
    OPTIONAL { ?item wdt:P1906 ?office . }
    FILTER NOT EXISTS { ?item wdt:P31 wd:Q3024240 }
    FILTER NOT EXISTS { ?item wdt:P576 [] }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "en" . }
  }
  ORDER BY ?itemLabel