ラギャ語
Bradley, D. (2007). "East and Southeast Asia." In C. Moseley (ed.), Encyclopedia of the world's endangered languages, pp. 349–424. London: Routledge.
Theraphan L.-Thongkum (en) (1992). "A Preliminary Reconstruction of Proto-Lakkja (Cha Shan Yao)." In The Mon–Khmer Studies Journal, 20: 57-90.