DJVU PDF Hayes, L.V.H. 1999, "On the track of Austric part III. basic vocabulary comparison", in The Mon-Khmer Studies Journal, vol. 29, pp. 1-34. cite.

DJVU PDF Suwilai Premsrirat. 1999, "So (Thavung)-English-Thai glossary Part II", in The Mon-Khmer Studies Journal, vol. 29, pp. 107-132. cite.