1. id Software: Wolfenstein Enemy Territory, under Downloads (September 29th 2007), http://www.enemyterritory.com/main.html
2. Valve Corporation: Half-Life 2 (April 29th 2007), http://half-life2.com/
3. Valve Corporation: CounterStrike: Source (accessed, February 8th 2008), http://counter-strike.net/
4. id Software: Enemy Territory Quake Wars (September 29th 2007), http://www.enemyterritory.com/
5. Armitage, G., Claypool, M., Branch, P.: Networking and Online Games - Under- standing and Engineering Multiplayer Internet Games, June 2006. John Wiley & Sons, Ltd, United Kingdom (2006)