Professor Gustous R Thripsted authored Flora and Fauna of the Universe, a guidebook mentioned by the Fourth Doctor. It discussed the true nature of the Usurians. (TV: The Sun Makers) As a youth, the Doctor had read an abridged version of this work. (PROSE: Lungbarrow) Thripsted co-wrote Introduction to Quantum Esotericism with Watkinson. This book discussed the Faction Paradox text known as the Book of Lies. (PROSE: Unnatural History)