query: # Members of the 57th United Kingdom Parliament with unknown Date of Birth
  SELECT ?person ?personLabel {
    ?person p:P39 [ ps:P39 wd:Q16707842; pq:P2937 wd:Q29974940 ] .
    FILTER NOT EXISTS { ?person wdt:P569 [] }
    SERVICE wikibase:label { bd:serviceParam wikibase:language 'en' }
  }
  ORDER BY ?personLabel