Dr Seuss
From Tardis Wiki, the free Doctor Who reference
Dr Seuss wrote the works contained in A Classic Case of Dr Seuss, which a young Grant had on a shelf in his bedroom. (TV: The Return of Doctor Mysterio)
According to the Sixth Doctor there was a planet devoted to the works of Doctor Seuss. He had been tempted to go there in the past, especially to try the green eggs and ham. (AUDIO: Trouble in Paradise)
Behind the scenes
The Sixth Doctor wanting try "green eggs and ham" is in reference to Suess's book of the same name.