D. Marx and J. Hutter, "General introduction to Car-Parrinello simulation"
http://pciwww.unizh.ch/pci/hutter/information/information.html

J. Hutter, "Introduction to Plane waves"
http://pciwww.unizh.ch/pci/hutter/information/information.html

Norm Conserving Pseudopotentials
http://www.sissa.it/cm/PWcodes/pseudo1.html

Ultrasoft   Pseudopotentials
http://www.physics.rutgers.edu/~dhv/uspp/