4 Privet Drive
From Tardis Wiki, the free Doctor Who reference
While serving time in prison, the Thirteenth Doctor started telling herself a "classic" bedtime story in order to pass the time: "Mr. and Mrs. Dursley of number four, Privet Drive, were proud to say that they were perfectly norm--". However, she was interrupted before she could continue. (TV: Revolution of the Daleks )
Behind the scenes
The line being quoted by the Doctor is the opening line of Harry Potter and the Philosopher's Stone. However, the book is not referred to by name in the episode. The full opening line reads "Mr. and Mrs. Dursley of number four, Privet Drive, were proud to say that they were perfectly normal, thank you very much."