Question: When did the mother of Joseph Stalin's child Vasily Dzhugashvili die?
SPARQL (Wikidata): SELECT ?value1 ?value2 WHERE { wd:Q855 p:P40 ?s . ?s ps:P40 wd:Q459216 . ?s pq:P570 ?value1 . ?s pq:P25 ?value2 }