APA (7th ed.) Citation

Duncan, J. C. (1946). Astronomy: A textbook (4th ed.). Harper.

Chicago Style (17th ed.) Citation

Duncan, John Charles. Astronomy: A Textbook. 4th ed. New York, London: Harper, 1946.

MLA (9th ed.) Citation

Duncan, John Charles. Astronomy: A Textbook. 4th ed. Harper, 1946.

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