Question: Name the scientist whose doctoral supervisor's doctoral student is John Bowlby?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?x onto:doctoralStudent <http://dbpedia.org/resource/John_Bowlby> . ?uri prop:doctoralAdvisor ?x  . ?uri rdf:type onto:Scientist}