what is the {start time} for {Rostov-on-Don} has {twinned administrative body} as {Gera} ?
In what year did the Rostov-on-Don begin as the twinned administrative body as Gera?
When did the Rostov-on-Don start as the twinned administrative body as Gera?
SELECT ?r WHERE { ?a property:twinned_administrative_body resource:Gera . resource:Rostov-on-Don property:twinned_administrative_body ?a . ?a property:start_time ?r }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q908> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P190> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q3750> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q908 p:P190 ?s . ?s ps:P190 wd:Q3750 . ?s pq:P580 ?value}