Question: Name the scientist whose supervisor was Ernest Rutherford and had a doctoral students named Charles Drummond Ellis?
SPARQL:
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/doctoralAdvisor> <http://dbpedia.org/resource/Ernest_Rutherford> . ?uri <http://dbpedia.org/property/doctoralStudents> <http://dbpedia.org/resource/Charles_Drummond_Ellis>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Scientist>}