Observations of the Tuigan Historian, Recording the Life of Yamun Khahan from his Rise to his Death in the Lands of the West, from Notes made for King Azoun of Cormyr, with the tentatively shortened title of A History of the Tuigan, was a book written by the lama Koja of Khazari in the early 1360s DR. It was, of course, about the Tuigan people of the Hordelands.
Following his Life among the Tuigan, Koja expanded his notes into his new book, aiming to give a complete account of Yamun Khahan, the Tuigan people, and their history. He wrote much of the book while staying at the temple of Deneir in the city of Procampur in the Vast, and was close to finishing it in the Year of the Helm, 1362 DR.
— A History of the Tuigan
The temple of Deneir was willing to make copies of the History and send it to all their fellow temples across the Heartlands. However, fictionalized accounts of the crusade against the Tuigan Horde, such as Lay of the Purple Dragons, prompted Koja to attempt to get his work mass-published and widely circulated, to present an honest version to the public, rather than it be buried in temple libraries. To this end, he sought the services of Forgemaster Inkstain and his new printing press. However, Inkstain quoted a price of 10,000 gold lions just for one copy, and 500 lions for extras, which Koja was unable to pay or raise the money for, not even after asking Duke Jozul Piniago.
It is not yet confirmed if and how the book was printed.