요사
The History of Liao, or Liao Shi (Liáo Shǐ), is a Chinese historical book compiled officially by the Mongol-led Yuan dynasty (1271–1368), under the direction of the historian Toqto'a (Tuotuo), and finalized in 1344. Based on Khitan's primary sources and other previous official Chinese records, it details the Khitan people, Khitan's tribal life and traditions, as well as the official histories of the Liao dynasty and its successor, the Western Liao dynasty.