Monty Python's Big Red Book

Monty Python's Big Red Book was one of the many volumes stored on the planet known as The Library. (DW: Silence in the Library)

Behind the scenes
Monty Python's Big Red Book was one of the better-known books based upon the 1969-74 TV comedy series Monty Python's Flying Circus, which in turn spun off a number of (plotwise unrelated) feature films. The Doctor Who franchise has a number of connections to Python, most notably in Douglas Adams, a contributor and occasional bit player in the original series who wrote for and served as script editor for the series in the late 1970s, and John Cleese who had a cameo in DW: City of Death. At one point or another virtually all of the lead actors in Monty Python were rumoured to be in consideration to play the Doctor.

Monty Python and The Holy Grail is referenced in PDA: Heart of TARDIS. When listing objects that had magical abilities, it ends the list with "...and swords of invincibility lobbed at passing knights by a samite-wearing woman in a pond." This appears to be a reference to the famous "Denice" scene in the film