DJVU PDF Benedict, P.K. 1985, "PST interrogative *ga(ng) ~ *ka", in Linguistics of the Tibeto-Burman Area, vol. 8, no. 1, pp. 1-10. cite.

DJVU PDF Clark, M. 1985, "Asking questions in Hmong and other Southeast Asian languages", in Linguistics of the Tibeto-Burman Area, vol. 8, no. 2, pp. 60-67. cite.

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 Luce, G.H. undated, "Riang interrogatives examples", in Luce Collection, MS 6574-7, pp. 051. National Library of Australia. cite.

DJVU PDF Razak, R.A. 2007, "Wh-interrogatives in the Malay classical text of Sulalatus Salatin", in SEALS VIII Papers from the 8th Annual Meeting of the Southeast Asian Linguistics Society 1998, ed. M. Alves et al., Canberra, Australia, pp. 135-147. Pacific Linguistics, Research School of Pacific and Asian Studies, The Australian National University. cite.