Question: How many first drivers have participated when Scuderia Ferrari was a first team?
SPARQL query:
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT COUNT(?uri) WHERE { ?x prop:firstTeam <http://dbpedia.org/resource/Scuderia_Ferrari> . ?x onto:firstDriver ?uri  . }