T. Schummer, S. Lukosch, and R. Slagter. Groupware: Design, Implementation, and Use, 11th International Workshop, CRIWG 2005, Lecture Notes in Computer Sciecne 3706, page 73-88. Berlin Heidelberg, Springer-Verlag, (2005)
M. Veit, and S. Herrmann. AOSD '03: Proceedings of the 2nd international conference on Aspect-oriented software development, page 140--149. New York, NY, USA, ACM, (2003)