Book of Rassilon

From Tardis Wiki, the free Doctor Who reference

The name of Book of Rassilon was applied to at least two very different Gallifreyan texts. One was a a religious text of the Time Lords, concerned with the Triumvirate, (PROSE: Cat's Cradle: Witch Mark, Lungbarrow) while the other was the illegible but powerful tome more accurately known as The Worshipful and Ancient Law of Gallifrey. (PROSE: Doctor Who and the Krikkitmen)