APA (7th ed.) Citation

Zhang, T., & Till, D. (1997). Teach yourself Perl 5 for Windows NT in 21 days. Sams.

Chicago Style (17th ed.) Citation

Zhang, Tony, and David Till. Teach Yourself Perl 5 for Windows NT in 21 Days. Indianapolis, Indiana: Sams, 1997.

MLA (9th ed.) Citation

Zhang, Tony, and David Till. Teach Yourself Perl 5 for Windows NT in 21 Days. Sams, 1997.