Book
The Travels of an Alchemist: The Journey of the Taoist Ch'ang-Ch'un from China to the Hindukush at the Summons of Chingiz Khan (Routledge / 'The Broadway Travellers' series, 1931)
Standard older English translation of the account of the Quanzhen master Qiu Chuji's journey across Central Asia to meet Genghis Khan in 1222.