query: #Jews in the Crown of Aragon with their teachers and students
  #defaultView:Graph
  SELECT ?personLabel ?person ?studentLabel ?student_of ?student_ofLabel 
  
  WHERE {
    ?person wdt:P140 wd:Q9268;
      wdt:P27 wd:Q204920.
    SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
    OPTIONAL { ?person wdt:P802 ?student. }
    OPTIONAL { ?person wdt:P1066 ?student_of. }
  }
  