An important 12th-century rhyme table traditionally attributed to the Song Dynasty scholar [[司马光|司馬光|si1 ma3 guang1]] (Sima Guang), used for studying historical Chinese phonology; it organizes the sounds of Chinese into twenty charts based on the thirty-six initials.

An important 19th-century phonological study by Chen Li of the Qing Dynasty, which pioneered the method of linking fanqie characters to reconstruct the sound system of the [[切韵|切韻|qie4 yun4]] dictionary.