Which country are the players of the Atletico Petroleos de Luanda from?
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/club> <http://dbpedia.org/resource/Atlético_Petróleos_de_Luanda_(handball)> . ?x <http://dbpedia.org/ontology/nationality> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Athlete>}
Atlético_Petróleos_de_Luanda_(handball)