What is {tributary} of {watercourse outflow} of {Po} ?
Name the tributary  that is the watercourse outflow of Po?
What tributary is the watercourse outflow of Po?
SELECT ?f WHERE { resource:Po property:mouth_of_the_watercourse ?l . ?l property:tributary ?f }
SELECT ?answer WHERE { ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q643> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P403>. ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?X . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?X. ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P974> . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?answer . }
SELECT ?answer WHERE { wd:Q643 wdt:P403 ?X . ?X wdt:P974 ?answer}
Po Sile Adige Tronto Erzen Aterno-Pescara Sangro Alento (Abruzzo) Feltrino Foro Osento Sinello Trigno Vjosë Seman Ishëm Rubicon Neretva Soča Piave Drin Brenta Vomano Bojana Cervaro Timavo Mat Cetina Jadro Cesano Krka Salinello Chienti Metauro Aso Carapelle Reno Foglia Tordino Marano Fortore Biferno Shkumbin Tagliamento Dragonja Ofanto Bevano Ombla Esino Conca Potenza Rječina Mirna Osapska reka Tesino Marecchia Tartaro-Canalbianco-Po di Levante Livenza Saline Trebišnjica Reka Lamone Savio Raša Ausa River Željeznica river Uniti Musone Po of Volano Rižana Žrnovnica Candiano Canal Canale Reale Misa Piomba Tenna Moro Old Drin