APA (7th ed.) Citation

Pratchett, T. (2004). Only you can save mankind (Corgi ed. publ. 1993, reissued.). Corgi Books.

Chicago Style (17th ed.) Citation

Pratchett, Terry. Only You Can Save Mankind. Corgi ed. publ. 1993, reissued. London: Corgi Books, 2004.

MLA (9th ed.) Citation

Pratchett, Terry. Only You Can Save Mankind. Corgi ed. publ. 1993, reissued. Corgi Books, 2004.