The History of the Time War

The History of the Time War was a book chronicling the history of the Last Great Time War. The Eleventh Doctor kept the only known copy of the book in his TARDIS' library, which Clara Oswald once looked through whilst running from a time zombie. Shortly thereafter she said that she had read the name of the Doctor in a book, presumably this one. The Doctor told her that this was dangerous knowledge, kept secret for a reason. She lost the knowledge of what she had read when the Doctor changed their timeline. (TV: Journey to the Centre of the TARDIS)