Question: Julia Donaldson's illustrated children's books include Room on the Broom, Stick Man and which story that has sold 13 million copies?
Sentence (from "The Gruffalo"): The Gruffalo is a children's book by writer and playwright Julia Donaldson, illustrated by Axel Scheffler, that tells the story of a mouse, the protagonist of the book, taking a walk in a European forest.
Relevant evidence: Yes