DJVU PDF Barker, M. 1969, "The phonological adaptation of French loanwords in Vietnamese", in The Mon-Khmer Studies Journal, vol. 3, pp. 138-147. cite.
DJVU PDF Barker, M.E. 1966, "Vietnamese-Muong tone correspondences", in Studies in Comparative Austroasiatic Linguistics, ed. N.H. Zide, pp. 9-25. Mouton & Co.. cite.