what is the {start time} for {Luxembourg} has {member of} as {International Centre for Settlement of Investment Disputes} ?
When did Luxembourg join the International Centre for Settlement of Investment disputes
What year did Luxembourg join the International Centre for Settlement of Investment Disputes?
SELECT ?a WHERE { ?i property:start_time ?a . resource:Luxembourg property:member_of ?i . ?i property:member_of resource:International_Centre_for_Settlement_of_Investment_Disputes }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q32> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P463> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q899770> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q32 p:P463 ?s . ?s ps:P463 wd:Q899770 . ?s pq:P580 ?value}