References

1. Bartle, A. R. (2003). Designing virtual worlds. Indianapolis: New Riders Publishing.

2. Kokswijk, J. van (2007): Digital ego. Social and legal aspects of virtual identity. Delft: Eburon.

3. Carr, Paull & Pond Graham ( 2007 ): The Unofficial tourist guide to Second Life. Publisher: St. Martin's Griffin.

4. Rymaszewski, M., Au, W. J. Wallace, M. Winters, C., Ondrejka, C., Batstone-Cunningham, B., et al. (2007): Second life. The official life. Indianapolis: Wiley Publishing.