What is {publication date} of {Team Fortress 2} that is {distribution} is {retail software} ?
What date was Team Fortress 2 published?
When was Team Fortress 2 (retail distribution) published?
SELECT ?i WHERE { resource:Team_Fortress_2 property:publication_date ?u . ?u property:distribution_format resource:retail_software . ?u property:publication_date ?i }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q382108> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P577> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P437> <http://wikidata.dbpedia.org/resource/Q7316614>
} 

SELECT ?obj WHERE { wd:Q382108 p:P577 ?s . ?s ps:P577 ?obj . ?s pq:P437 wd:Q7316614 }