APA (7th ed.) Citation

Toons, Brown, & Jarret. (1989). Your heart and lungs. Harrap Books.

Chicago Style (17th ed.) Citation

Toons, Brown, and Jarret. Your Heart and Lungs. London: Harrap Books, 1989.

MLA (8th ed.) Citation

Toons, et al. Your Heart and Lungs. Harrap Books, 1989.