APA (7th ed.) Citation

Roy, A. E., & Clarke, D. (1987). Astronomy: Principles and practice (3rd ed.). A. Hilger.

Chicago Style (17th ed.) Citation

Roy, A. E., and D. Clarke. Astronomy: Principles and Practice. 3rd ed. Bristol: A. Hilger, 1987.

MLA (9th ed.) Citation

Roy, A. E., and D. Clarke. Astronomy: Principles and Practice. 3rd ed. A. Hilger, 1987.