Name the river with mouth as Thames Estuary and passes through Reading Berkshire ?
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/riverMouth> <http://dbpedia.org/resource/Thames_Estuary> . ?uri <http://dbpedia.org/property/city> <http://dbpedia.org/resource/Reading,_Berkshire>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/River>}
Thames_Estuary Reading,_Berkshire