1. Aristotle (1999). The Nicomachean Ethics, 2nd ed. (trans. Terence Irwin). Cambridge: Hackett Publishing Company.
2. Biggs, S. (2000). “Charlotte’s Web:” how one woman weaves positive relationships on the net. Cyberpsychology and Behavior, 3(4), 655–663.
3. Boase, J., & Wellman, B. (2005). Personal relationships: on and off the internet. In D. Perlman & A. L. Vangelisti (Eds.), Handbook of personal relations (pp. 709–723). Oxford: Blackwell.
4. Boellstorff, T. (2008). Coming of age in second life: an anthropologist explores the virtual human. Princeton: Princeton University Press.
5. Briggle, A. (2008). Real friends. how the Internet can foster friendship. Ethics and Information Technology 10(1), 71–79