APA (7th ed.) Citation

Ahlberg, J., & Ahlberg, A. (1982). The ha ha bonk book. Puffin Books a div. of Penguin Books.

Chicago Style (17th ed.) Citation

Ahlberg, Janet, and Allan Ahlberg. The Ha Ha Bonk Book. Harmondsworth, Middlesex: Puffin Books a div. of Penguin Books, 1982.

MLA (9th ed.) Citation

Ahlberg, Janet, and Allan Ahlberg. The Ha Ha Bonk Book. Puffin Books a div. of Penguin Books, 1982.

Warning: These citations may not always be 100% accurate.