APA (7th ed.) Citation

Sidgwick, J. B. (1944). Introductory astronomy: A guide for night watchers. Philosophical library.

Chicago Style (17th ed.) Citation

Sidgwick, J. B. Introductory Astronomy: A Guide for Night Watchers. New York: Philosophical library, 1944.

MLA (9th ed.) Citation

Sidgwick, J. B. Introductory Astronomy: A Guide for Night Watchers. Philosophical library, 1944.

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