With his monograph “Phonetics of the Mường Language across Dialects”, Dr. Nguyễn Văn Tài was the first scholar to conduct a comprehensive survey and description of Mường phonetics across its dialects, from which he divided them into three regions: Northern (Sơn La, Hà Giang, Tuyên Quang, Lào Cai, Yên Bái), Central (Hòa Bình and its surrounding areas), and Southern (Nghệ An, Hà Tĩnh, Quảng Bình). The 350-page work is accompanied by three appendices: a comparative study of Việt–Mường phonology, a lexical comparison of nearly 1,000 words across 30 sub-dialects, and 34 maps of dialectal phenomena. “Phonetics of the Mường Language across Dialects” is a work of both theoretical and practical significance, invaluable for research on the Mường language and the history of Vietnamese, and it rightfully deserves a place in the linguistic bookshelf.