The Bru, also known as the Baru, B'ru, and Leu, are a group numbering about 50,000 in 1985 with 40,132 in Vietnam and the remainder in neighboring Laos. They are linguistically and culturally related to the nearby Kalo (Ca Lo, Ka Lo) and some experts suggest that the Kalo are best classified as a Bru subgroup.
LeBar, Frank M., Gerald C. Hickey, and John K. Musgrave, eds. (1964). Ethnic Groups of Mainland Southeast Asia, 138. New Haven: HRAF Press.