^ abWurm, Stephen Adolphe; Li, Rong; Baumann, Theo; Lee, Mei W. (1987). Language Atlas of China. Longman. p. B-12. ISBN978-962-359-085-3.
Norman, Jerry (1974), "The initials of Proto-Min", Journal of Chinese Linguistics, 2 (1): 27–36, JSTOR23749809. (includes a description of the phonology of the Yong'an dialect)