What is {head of government} of {North Rhine-Westphalia} that is {start time} is {1956-2-20} ?
Who was the head of the government of north Rhine-Westphalia beginning in 1956-2-20?
What is the head of government of north Rhine -Westphalia that has start time is 1956-2-20?
SELECT ?e WHERE { resource:North_Rhine-Westphalia property:head_of_government ?n . ?n property:head_of_government ?e . ?n property:start_time ?d . FILTER ( CONTAINS ( YEAR ( ?d ) , '1956' ) ) }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q1198> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P6> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P580> <1956-2-20>
} 

SELECT ?obj WHERE { wd:Q1198 p:P6 ?s . ?s ps:P6 ?obj . ?s pq:P580 ?x filter(contains(YEAR(?x),'1956')) }