DJVU PDF Purnell, H.C. 2002, "Steps Toward Standardization of a Minority Orthography: An Update on Mien (Yao)", in Papers from the Tenth Annual Meeting of the Southeast Asian Linguistics Society, ed. M. Macken, pp. 297-316. Arizona State University, Program for Southeast Asian Studies. cite.

DJVU PDF Purnell, H.C. 1998, "Putting it all together: Components of a secular song in Iu Mien", in Papers from the Fifth Annual Meeting of the Southeast Asian Linguistics Society, ed. S.L. Chellian and W.J.D. Reuse, pp. 277-302. Arizona State University, Program for Southeast Asian Studies. cite.

DJVU PDF Purnell, H.C. 1987, "Developing practical orthographies for the Iu Mien (Yao), 1932 - 1986: a case study", in Linguistics of the Tibeto-Burman Area, vol. 10, no. 2, pp. 128-141. cite.

DJVU PDF Purnell, H.C. 1972, "Toward Contrastive Analysis Between Thai and Hill Tribe Languages: Some Phonetic Data", in A Conference on Tai Phonetics and Phonology, ed. J.G. Harris and R.B. Noss, pp. 113-130. Mahidol University. cite.