APA Style

Geronimo, S. (2009). Geronimo Stilton: Thea Stilton and the secret of the old castle (1st edition). London: Scholastic.

MLA Style

Geronimo, Stilton. "Geronimo Stilton: Thea Stilton and the secret of the old castle". 1st edition London: Scholastic, 2009. Textbook.