Xu Chan 徐蕆 was a 12th-century scholar, who wrote a preface to the 韻補 Yunbu of 吳域 Wu Yu (circa 1100–1154) in which he first proposed the xiesheng hypothesis.[1]
Behr, Wolfgang. 2005. "Language Change in premodern China: notes on its perception and impact on the idea of a 'constant way'." Historical truth Historical Criticism and Ideology: Chinese Historiography and Historical Culture from a New Comparative Perspective. Helwig Schmidt-Glintzerr, Achim Mittag, and Jörn Rüsen, eds. pp. 13-51, esp. 34.
