APA (7th ed.) Citation

Anne Digby. (1999). The Naughtiest Girl keeps a secret. Hodder Children's Books.

Chicago Style (17th ed.) Citation

Anne Digby. The Naughtiest Girl Keeps a Secret. Great Britain: Hodder Children's Books, 1999.

MLA (9th ed.) Citation

Anne Digby. The Naughtiest Girl Keeps a Secret. Hodder Children's Books, 1999.