APA (7th ed.) Citation

Janet Ahlberg & Allan Ahlberg. (1993). The jolly postman, or, Other people's letters. Heinemann.

Chicago Style (17th ed.) Citation

Janet Ahlberg and Allan Ahlberg. The Jolly Postman, or, Other People's Letters. London [England]: Heinemann, 1993.

MLA (9th ed.) Citation

Janet Ahlberg and Allan Ahlberg. The Jolly Postman, or, Other People's Letters. Heinemann, 1993.