DJVU PDF Hargreaves, D. 1996, "From interrogation to topicalization: Proto-Tibeto-Burman *la in Kathmandu Newar", in Linguistics of the Tibeto-Burman Area, vol. 19, no. 2, pp. 31-44. cite.

DJVU PDF Fuller, J.W. 1987, "Topic markers in Hmong", in Linguistics of the Tibeto-Burman Area, vol. 10, no. 2, pp. 113-127. cite.