What is {chairperson} of {United Russia} that is {start time} is {2001-1-1} ?
Who was Russia's chairperson on 1/1/2001?
Who was the Chairperson of United Russia beginning on January 1, 2001?
SELECT ?k WHERE { ?f property:start_time ?c . resource:United_Russia property:chairperson ?f . FILTER ( CONTAINS ( YEAR ( ?c ) , '2001' ) ) . ?f property:chairperson ?k }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q151469> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P488> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P580> <2001-1-1>
} 

SELECT ?obj WHERE { wd:Q151469 p:P488 ?s . ?s ps:P488 ?obj . ?s pq:P580 ?x filter(contains(YEAR(?x),'2001')) }