APA (7th ed.) Citation

Ridpath, I., & Tirion, W. (1987). The monthly sky guide. Cambridge University Press.

Chicago Style (17th ed.) Citation

Ridpath, Ian, and Wil Tirion. The Monthly Sky Guide. Cambridge: Cambridge University Press, 1987.

MLA (9th ed.) Citation

Ridpath, Ian, and Wil Tirion. The Monthly Sky Guide. Cambridge University Press, 1987.