User:TweetsFactsAndQueries/Queries/doctoral theses with more than one author

Originally posted on Twitter and on Mastodon.

# doctoral theses with more than one (best-rank) author
SELECT ?thesis ?thesisLabel (GROUP_CONCAT(?authorLabel; separator = ", ") AS ?authors)
WITH {
  SELECT ?thesis WHERE {
    ?thesis wdt:P31/(wdt:P279|wdt:P460)* wd:Q187685;
            wdt:P50 ?author.
  }
  GROUP BY ?thesis
  HAVING(COUNT(?author) > 1)
} AS %theses
WHERE {
  INCLUDE %theses.
  ?thesis wdt:P50 ?author.
  SERVICE wikibase:label {
    bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en,fr,de".
    ?thesis rdfs:label ?thesisLabel.
    ?author rdfs:label ?authorLabel.
  }
}
GROUP BY ?thesis ?thesisLabel
ORDER BY DESC(COUNT(?author))

Try it!