APA (7th ed.) Citation

Pratchett, T., Briggs, S., & Kidby, P. (1998). A tourist guide to Lancre. Corgi.

Chicago Style (17th ed.) Citation

Pratchett, Terry, Stephen Briggs, and Paul Kidby. A Tourist Guide to Lancre. London: Corgi, 1998.

MLA (9th ed.) Citation

Pratchett, Terry, et al. A Tourist Guide to Lancre. Corgi, 1998.