“The Linux-PAM Application Developers' Guide” by Andrew G. Morgan: www.kernel.org/pub/linux/libs/pam/Linux-PAM-html/pam_appl.html
“The Linux-PAM Module Writers' Guide” by Andrew G. Morgan: www.kernel.org/pub/linux/libs/pam/Linux-PAM-html/pam_modules.html
“The Linux-PAM System Administrator's Guide” by Andrew G. Morgan: www.kernel.org/pub/linux/libs/pam/Linux-PAM-html/pam.html
Linux-PAM Source Code: ftp.kernel.org/pub/linux/libs/pam/
