Waterstone's
From Tardis Wiki, the free Doctor Who reference
There was a Waterstone's across the street from Sanderson & Grainger in Colchester. (TV: Closing Time)
It was seen to sell books. (TV: The Curse of Clyde Langer)
In 1995, the chain sold copies of Paul Magrs' novel, Marked for Life. After only six months, they placed the copies of the book in "bargain bins" - while Paul was upset that his book had ended up like that, he wasn't too worried, as it was one of the things that sparked his relationship with Jeremy. (PROSE: The Story of Fester Cat)
Behind the scenes
Waterstone's is a book store chain, known for selling Doctor Who literature and graphic novels.