query: embed.html#SELECT ?work ?workLabel ?david1Label ?david2Label WHERE {
    ?work wdt:P31/wdt:P279* wd:Q571;
          wdt:P50 ?david1, ?david2.
    wd:Q18057751 ^wdt:P735 ?david1, ?david2.
    FILTER(STR(?david1) < STR(?david2))
    FILTER NOT EXISTS {
      ?work wdt:P50 ?otherAuthor.
      FILTER(?otherAuthor != ?david1 && ?otherAuthor != ?david2)
    }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
  }
  ORDER BY ?work