APA (7th ed.) Citation

Ridpath, I., & Tirion, W. (1993). The monthly sky guide (3rd ed.). Cambridge University Press.

Chicago Style (17th ed.) Citation

Ridpath, Ian, and Wil Tirion. The Monthly Sky Guide. 3rd ed. Cambridge [England] ; New York, NY, USA: Cambridge University Press, 1993.

MLA (9th ed.) Citation

Ridpath, Ian, and Wil Tirion. The Monthly Sky Guide. 3rd ed. Cambridge University Press, 1993.