1. Chan, H., Lee, R., Dillon, T., & Chang, E. (2002). E-commerce—fundamentals and applications. Brisbane: Wiley.
2. www.amazon.com . www.firebox.com .
3. World of Warcraft. www.worldofwarcraft.com .
4. Eve Online. www.eveonline.com .
5. Everquest 2 (2004). Sony Online Entertainment.