3Aarseth, Espen. Aporia and Epiphany in Doom and The Speaking Clock.The Temporality of Ergodic Art [ A ]//Ryan, Marie- Laure. In Cyberspace Textuality. Computer technology and literary theory. Bloomington & Indianapolis : Indiana University Press, 1999 :pp. 32- 34.
4Helm, Michael Virtual Realism [ M 1- New York : Oxford University Press, 1998 ,pp.51-52.
5Holtzmaan, Steven. Digital Mosaic : the Aesthetic of Cyberspace E M ]. New York : Simon & Schuster, 1997 : p. 111.
6Landow, George, and Paul Delany. Hypertext, Hypermedia and Liter- ary Studies. The State of the Art [ A ]//Paul Dclany, and George P. Landow. 1991.In Hypermedia and Literary Studies. Combridge, Mass- ehusetts and London, England : The MIT Press, 1991. Fourth printing, 1994 :pp.9-14.
