Beginning Ubuntu for Windows and Mac Users
Nathan Haines
American Lit 101
Brianne Keith
Programming PHP
Kevin Tatroe & Peter MacIntyre
Help Your Boss Help You
Ken Kousen
Intermediate Perl: Beyond the Basics of Learning Perl
Randal L. Schwartz & Brian D Foy & Tom Phoenix
Learning Perl
Perl One-Liners
Peteris Krumins
Mastering Perl
Brian D Foy
Programming Perl
Tom Christiansen & Brian D Foy & Larry Wall & Jon Orwant