For those with a developer central account there is additional information at the following: https://www.sgi.com/developers/devnews/2000/q1_00/d-performer_4_linux-q1_00.html
http://www.sgi.com/software/performer/linux-faq.html
http://pauillac.inria.fr/~xleroy/linuxthreads/
http://www.LambdaCS.com/newsgroup/FAQ.html
http://metalab.unc.edu/pub/Linux/docs/faqs/Threads-FAQ/html/ThreadLibs.html
http://metalab.unc.edu/pub/Linux/docs/faqs/Threads-FAQ/html/LearnMore.html
http://www.tronche.com/gui/x/xlib/display/XInitThreads.html
http://lclint.cs.virginia.edu/
http://www.virtualprototypes.com/
Unix Network Programming, by Stevens
Advanced Programming in the Unix Environment, by Stevens
POSIX Programmer's Guide, by Lewine
POSIX.4: Programming for the Real World, by Gallmeister
Managing Projects with Make, by Oram & Talbott
Pthreads Programming, by Nichols, Buttlar and Farrel