What is {date of birth} of {Polybius} that is {sourcing circumstances} is {circa} ?
Give the birth date of Polybius?
When was Polybius born?
SELECT ?k WHERE { ?g property:date_of_birth ?k . resource:Polybius property:date_of_birth ?g . ?g property:sourcing_circumstances resource:circa }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q131169> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P569> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P1480> <http://wikidata.dbpedia.org/resource/Q5727902>
} 

SELECT ?obj WHERE { wd:Q131169 p:P569 ?s . ?s ps:P569 ?obj . ?s pq:P1480 wd:Q5727902 }