Essays on the Khitans written by Kh. Perenlei (Perlee). The Khitans were nomadic people who established the Liao Empire (907-1125). Extent and format of original material: Manuscript. Owner(s) of original material: Mongolian Academy of Sciences, Institute of History and Ethnography. Author(s) of original material: Kh. Perenlei (Perlee). Original institution reference: F-5, D-1, HN-210b.