Question: Who is the scientist whose doctoral student is Erich Bagge?
SPARQL:
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/doctoralStudent> <http://dbpedia.org/resource/Erich_Bagge>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Scientist>}