The Doctor's Dilemma

 was a book by George Bernard Shaw.

Trix once woke up while the TARDIS was in flight and caught the Eighth Doctor reading it. When called on it, the Doctor then launched into a brief account of how he'd bet Shaw at a party hosted by Oscar Wilde. (PROSE: The Gallifrey Chronicles)

The Doctor added the book to his collection at least by his seventh incarnation, who once mentioned having it while on Iceworld. (TV: Dragonfire)