FOR HOW LONG DID NOBEL PEACE PRIZE WINNER, INVOLVED IN UNEF ESTABLISHMENT, PRIME MINISTER OF CANADA?
Lester B. Pearson:  He was the 14th Prime Minister of Canada from 22 April 1963 to 20 April 1968, as the head of two back-to-back Liberal minority governments following elections in 1963 and 1965.
i don't know