what is the {sourcing circumstances} for {Owain Glyndŵr} has {date of death} as {1416-0-0} ?
Owain Glyndwr died in 1416 of what cause?
How did Owain Glyndwr die in 1416?
SELECT ?n WHERE { ?q property:sourcing_circumstances ?n . ?q property:date_of_death ?c . resource:Owain_Glyndŵr property:date_of_death ?q . FILTER ( CONTAINS ( YEAR ( ?c ) , '1416' ) ) }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q317279> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P570> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <1416-0-0> .
?statement <http://www.wikidata.org/entity/P1480> ?value. 
} 

SELECT ?value WHERE { wd:Q317279 p:P570 ?s . ?s ps:P570 ?x filter(contains(YEAR(?x),'1416')) . ?s pq:P1480 ?value}