The Oy (also spelled Huei or Oi) are a group of about 10,000 (1981) located on the slopes of the Boloven plateau in Attopeu Province in southern Laos. A subgroup, the The, are considered by some to be a distinct group, although they may now be totally assimilated. The influence of both Buddhism and Roman Catholicism has altered their traditional way of life.
Hickey, Gerald C. (1964). "Oy." In Ethnic Groups of Mainland Southeast Asia, edited by Frank M. LeBar, Gerald C. Hickey, and John K. Musgrave, 145. New Haven: HRAF Press.