IBM: POSIX threads explained
https://www.ibm.com/developerworks/library/l-posix1/index.html
Hilos Posix: pthreads
https://computing.llnl.gov/tutorials/pthreads/
CreatingThreads
Example: Pthread Creation and Termination
https://computing.llnl.gov/tutorials/pthreads/#CreatingThreads