The Lion, the Witch and the Wardrobe

The Lion, the Witch and the Wardrobe was a book by C. S. Lewis. The Eleventh Doctor and Amy Pond inspired its creation by giving Lewis a copy of The Professor, the Queen and the Bookshop. (DWM: The Professor, the Queen and the Bookshop)

Bobby Prescott compared escaping into books to going through doorways into other worlds, like the wardrobe into Narnia, which was one of the first books he read. (NA: Cat's Cradle: Warhead)

The Eighth Doctor referred to "happening upon wardrobe adventures", a central feature in the book's plot. (EDA: EarthWorld)

Iris Wildthyme pondered about entering Narnia when she was swallowed by the New Gods of Valcea who were sentient wardrobes. (IW: Enter Wildthyme)

Behind the scenes
The comic story The Professor, the Queen and the Bookshop and the television story The Doctor, the Widow and the Wardrobe are both conscious homages to The Lion, the Witch and the Wardrobe, with visual and plot elements drawn from Lewis's story. The short story "The Lying Old Witch in the Wardrobe", however, merely puns on the book's title.