What is the scientist whose PhD students are Erich Bagge and Serban Titeica?
SELECT DISTINCT ?uri WHERE { ?uri <http://dbpedia.org/property/doctoralStudents> <http://dbpedia.org/resource/Erich_Bagge> . ?uri <http://dbpedia.org/property/doctoralStudents> <http://dbpedia.org/resource/Șerban_Țițeica> . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Scientist>}
Erich_Bagge Șerban_Țițeica