Question: Give me all female Russian astronauts.
SPARQL:
PREFIX yago: <http://dbpedia.org/class/yago/>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT DISTINCT ?uri ?string 
WHERE {
	?uri rdf:type yago:RussianCosmonauts .
        ?uri rdf:type yago:FemaleAstronauts .
        OPTIONAL { ?uri rdfs:label ?string. FILTER (lang(?string) = 'en') }
}