Question: Among the scientist known for Manhattan Project who had a doctoral student named Charles Ellis ?
SPARQL:
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/property/doctoralStudents> <http://dbpedia.org/resource/Charles_Drummond_Ellis> . ?uri <http://dbpedia.org/property/knownFor> <http://dbpedia.org/resource/Manhattan_Project>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Scientist>}