DJVU PDF Watters, S.A. 2002, "The sounds and tones of five Tibetan languages of the Himalayan region", in Linguistics of the Tibeto-Burman Area, vol. 25, no. 1, pp. 1-65. cite.

DJVU PDF Hyman, L.M. and Kenneth, V. 2002, "Tone and stem2-formation in Hakha Lai", in Linguistics of the Tibeto-Burman Area, vol. 25, no. 1, pp. 113-121. cite.