DJVU PDF Ferlus, M. 1979, "Formation des registres et mutations consonantiques dans les langues Mon-Khmer", in The Mon-Khmer Studies Journal, vol. 8, pp. 1-76. cite.

DJVU PDF Pinnow, H.-J. 1979, "Reflections on the history of the Khmer phonemic system", in The Mon-Khmer Studies Journal, vol. 8, pp. 103-130. cite.