APA (7th ed.) Citation

Pratchett, T., & Briggs, S. (2001). The Discworld companion (Updated.). Gollancz.

Chicago Style (17th ed.) Citation

Pratchett, Terry, and Stephen Briggs. The Discworld Companion. Updated. London: Gollancz, 2001.

MLA (9th ed.) Citation

Pratchett, Terry, and Stephen Briggs. The Discworld Companion. Updated. Gollancz, 2001.

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