1. Bricken, M.: Virtual Reality Learning Environments: Potentials and Challenges. Computer Graphics 25, 178–184 (1991)
2. History of the Greek nation volume B’, Ekdotike Athenon, Athens (1971)
3. Herodotus, Rawlinson, G. (Trns): The History of Herodotus: Polymnia (2005)
4. Roberts, D.F., Foehr, U.G., Rideout, V.J., Generation, M.: Media in the Lives of 8-18 year-olds. Kaiser Family Foundation, Menlo Park (2005)
5. Lecture Notes in Computer Science;E.A.-L. Lee,2008