 Nonetheless, the "Liao Shi" provides a large amount of knowledge on Khitan's imperium's tribal politics and traditions.Since Yelü Yan's "Shilu" and Chen Daren's "Liao Shi" have been lost, Toqto'a's "Liao Shi" is the only extant Chinese-style historical record of the Khitan empire.The work of collation and punctuation have been done several times, by example in the Qianlong edition, the Nanjian edition, the Beijian edition, Baina edition and the Daoguang edition.The nowadays commonly use edition is the Zhonghua Shuju Press edited "Liao Shi", under direction of the Khitan studies' specialists Feng Jiasheng and Chen Shu, and based on the Baina edition.