When did Nigel Farage started to work at Refco and when did he leave?
SELECT ?value1 ?value2 WHERE { wd:Q318471 p:P108 ?s . ?s ps:P108 wd:Q2136640 . ?s pq:P582 ?value1 . ?s pq:P580 ?value2 }
nigel farage: Q318471 refco: Q2136640