DJVU PDF Goral, D.R. 1988, "Modal verbs and generative grammar", in Linguistics of the Tibeto-Burman Area, vol. 11, no. 2, pp. 7-24. cite.
DJVU PDF Manaster-Ramer, A. 1988, "What about Lisu?", in Linguistics of the Tibeto-Burman Area, vol. 11, no. 2, pp. 133-143. cite.