what is the {position held} for {Pridnestrovian Moldavian Republic} has {head of state} as {Yevgeny Shevchuk} ?
At what time was Yevgeny Shevchuk the head of state of the Pridnestrovian Moldavian Republic?
When did the Pridnestrovian Moldavian Republic have the head of state of Yevgeny Shevchuk?
SELECT ?j WHERE { ?f property:position_held ?j . resource:Transnistria property:head_of_state ?f . ?f property:head_of_state resource:Yevgeny_Shevchuk }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q907112> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P35> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q188409> .
?statement <http://www.wikidata.org/entity/P39> ?value. 
} 

SELECT ?value WHERE { wd:Q907112 p:P35 ?s . ?s ps:P35 wd:Q188409 . ?s pq:P39 ?value}