APA (7th ed.) Citation

Richards, J. P., & Williams, R. P. (1972). Waves. Penguin books.

Chicago Style (17th ed.) Citation

Richards, John P., and Rhys P. Williams. Waves. Harmondsworth: Penguin books, 1972.

MLA (9th ed.) Citation

Richards, John P., and Rhys P. Williams. Waves. Penguin books, 1972.