APA (7th ed.) Citation

Feynman, R. P. (1999). Feynman lectures on gravitation. Penguin Books.

Chicago Style (17th ed.) Citation

Feynman, Richard P. Feynman Lectures on Gravitation. London: Penguin Books, 1999.

MLA (9th ed.) Citation

Feynman, Richard P. Feynman Lectures on Gravitation. Penguin Books, 1999.