Whether or not the Biao people of China are of Kam-Sui descent is an issue of present debate in the scientific community. They are, however, a Tai ethnic group.
Kang people
The Kang people of Yunnan Province (referred to as Tai Khang in Laos) speak a Kam–Sui language, but ethnically descend from the Dai people.
Kam–Sui of Vietnam
The following Kam–Sui ethnic groups originating in China have population clusters in Vietnam:
The Tai Khang people of Laos (referred to as Kang in China) speak a Kam–Sui language, but ethnically descend from the Dai people.
References
^Edmondson, Jerold A. and David B. Solnit, editors. 1988. Comparative Kadai: Linguistic studies beyond Tai. Summer Institute of Linguistics and the University of Texas at Arlington Publications in Linguistics, 86. Dallas: Summer Institute of Linguistics and the University of Texas at Arlington. vii, 374 p.
^Edmondson, Jerold A. and David B. Solnit, editors. 1997. Comparative Kadai: the Tai branch. Summer Institute of Linguistics and the University of Texas at Arlington Publications in Linguistics, 124. Dallas: Summer Institute of Linguistics and the University of Texas at Arlington. vi, 382 p.
^Ostapirat, Weera. (2000). "Proto-Kra." Linguistics of the Tibeto-Burman Area23 (1): 1-251.