... Southeast Asia is home to 5 language families, namely Sino – Tibetan, Austroasiatic, Austronesian, Tai – Kadai, and Miao-Yao [emphasis TTD’s, 1999]. Vietnam regarded as a linguistic miniature of ... order, the two Austroasiatic originating names Phú Lương and Lô Giang may be first ranked, the Tai-Kadai term Thao and the Austroasiatic name Cái stand on the second position, and the last is Hồng/Hồng ... between Austroasiatic and Tai-Kadai speaking inhabitants when the river seems to be the Southwestern boundaries of Tai-Kadai geographical distribution. The Austroasiatic and Tai-Kadai toponyms, then,...