Oolon Colluphid

Oolon Colluphid was the author of a book, Origins of the Universe, which the Fourth Doctor had in his pocket as a way to pass the time when pinned down by fallen rubble. Paging through the book, Doctor snorted and spoke of Colluphid's ignorance. (DW: Destiny of the Daleks)

Behind the scenes
The character of Oolon Colluphid was mentioned in Douglas Adams' The Hitchhiker's Guide to the Galaxy. Adams served as Script Editor for Destiny of the Daleks and occasional Doctor Who script writer. The Hitchhiker's Guide series also exists as a fictional work in the Doctor Who universe. However, due to the existence of the book in Destiny of the Daleks, it is possible that some elements of The Hitchhiker's Guide to the Galaxy do in fact exist within the Doctor Who universe. Cross-dimensional travel has been utilized on more than one occsaion in both properties, so it's possible that the book might not even be from the regular Doctor Who universe.