Question: How many nations' volleyball players have played for the Russian women volleyball team?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:nationalteam <http://dbpedia.org/resource/Russia_women's_national_volleyball_team> . ?x prop:placeOfBirth ?uri . ?uri rdf:type onto:Country}