Question: Where is the mouth of the river whose tributary is Bjelimićka  Rijeka ?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/rightTributary> <http://dbpedia.org/resource/Bjelimićka_Rijeka> . ?x <http://dbpedia.org/ontology/mouthCountry> ?uri . }