APA (7th ed.) Citation

Wall, L., & Schwartz, R. L. (1991). Programming Perl. O'Reilly.

Chicago Style (17th ed.) Citation

Wall, Larry, and Randal L. Schwartz. Programming Perl. Sebastopol, Calif: O'Reilly, 1991.

MLA (9th ed.) Citation

Wall, Larry, and Randal L. Schwartz. Programming Perl. O'Reilly, 1991.