What is the {human} for {doctoral student} of {Jonas Salk}
Who was Jonas Salk's doctoral understudy?
Who was Jonas Salk's doctoral student?
SELECT DISTINCT ?c WHERE { ?c rdf:type ontology:human . resource:Jonas_Salk property:doctoral_student ?c }
select distinct ?obj where { ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q200101> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P185> . ?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj . ?obj <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q5> } 
 select distinct ?obj where { wd:Q200101 wdt:P185 ?obj . ?obj wdt:P31 wd:Q5 } 
Robert Lanza