1. http://www.aol.com/aim/home.html (03-06-2001)
2. http://web.icq.com/(03-06-2001)
3. Jaaskelainem, K.: Strategic Questions in the Development of Interactive Television Programs, Publication series of the University of Art and Design Helsinki UIAR A 31, Ph.D. Thesis, Media Laboratory of University of Arts and Design, Helsinki (2001)
4. Voes, L.: Searching for the Holy Grail — Images of Interactive Television, MSc. Dissertation, University of Utrecht, Department of Media and Communication, Amsterdam (2000)
5. Stewart, J.: Interactive television at home: Television meets the Internet. In: Interactive Television. TV of the Future or the Future of TV? Aalborg University Press-Media & Cultural Studies 1 (1999) 232–233