# Show US presidents and their children who attended the same school
SELECT DISTINCT ?presidentLabel ?childLabel  ?schoolLabel
WHERE {
  ?president wdt:P39 wd:Q11696;
         wdt:P40 ?child;
         wdt:P69 ?school. 
  ?child wdt:P69 ?school.
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en".}
 }
ORDER BY ?presidentLabel