APA (7th ed.) Citation

Schrank, D., Guetl, C., & Kappe, F. (2010). Design and Implementation of a Payment System for Virtual Worlds. World Academy of Science, Engineering and Technology.

Chicago Style (17th ed.) Citation

Schrank, D., Christian Guetl, and F. Kappe. Design and Implementation of a Payment System for Virtual Worlds. World Academy of Science, Engineering and Technology, 2010.

MLA (9th ed.) Citation

Schrank, D., et al. Design and Implementation of a Payment System for Virtual Worlds. World Academy of Science, Engineering and Technology, 2010.