Sources

Alessi, Jeremy. "Games Demystified: Portal" .www.gamasutra.com. 26 Aug 2008. http://www.gamasutra.com/view/feature/3770/games_demystified_portal.php?page=1

Eberly, David H. Game Physics. San Francisco, CA. Morgan Kaufmann Publishers. 2004.

Henry, Calen & Karsemeyer, Jacob ."Physics in Mass Market Games". www.gamecareerguide.com. 26 Aug 2008. http://www.gamecareerguide.com/features/534/physics_in_mass_market_.php

Millington, Ian. Game Physics Engine Development. San Francisco, CA. Morgan Kaufmann Publishers. 2007.

Palmer, Grant. Physics for Game Developers. New York, NY. Apress 2005.

Walker, Jearl. Fundmentals of Physics, 8th Edition. United States. John Wiley & Sons, Inc. 2008.