APA (7th ed.) Citation

Duncan, J. C. (1955). Astronomy: A textbook (5th ed.). Harper.

Chicago Style (17th ed.) Citation

Duncan, John Charles. Astronomy: A Textbook. 5th ed. New York: Harper, 1955.

MLA (9th ed.) Citation

Duncan, John Charles. Astronomy: A Textbook. 5th ed. Harper, 1955.