What is {discoverer of} of {vitamin A}, that has {birth year} is {1887-9-16} ?
What person born on 1887-9-16 discovered vitamin A?
SELECT ?answer WHERE { wd:Q18225 wdt:P61 ?answer . ?answer wdt:P569 ?x FILTER(contains(YEAR(?x),'1887'))}
SELECT ?answer WHERE { ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q18225> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P61>. ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?answer . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?answer. ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P569> . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <1887-9-16> . }
What individual born on 1887-9-16 observed vitamin A?