Roth, Jörg; Unger, Claus (2000): An extensible classification model for distribution architectures of synchronous groupware. COOP 2000: Cooperative Systems Design - The Use of Theories and Models. IOS Press. ISBN: 1-58603-042-6. pp. 113-128. Architectures for Cooperative Systems (1). Sophia-Antipolis, February. 23-26 May 2000