APA (7th ed.) Citation

Gregory, R. L. (1969). Rays of hope: The universe, life, man. Philosophical Library.

Chicago Style (17th ed.) Citation

Gregory, Robert Lloyd. Rays of Hope: The Universe, Life, Man. New York: Philosophical Library, 1969.

MLA (9th ed.) Citation

Gregory, Robert Lloyd. Rays of Hope: The Universe, Life, Man. Philosophical Library, 1969.

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