D. Schuler. Proceedings of the Conference on Participatory Design (PDC '02) (Malmö, Sweden, June 23-25, 2002), page 434-436. Palo Alto, CA, 2000, CPSR, (2002)
J. Gómez-Romero, F. Bobillo, and M. Delgado. Proceedings of the 6th International Semantic Web Conference and 2nd Asian Semantic Web Conference (ISWC/ASWC2007), Busan, South Korea, volume 4825 of LNCS, page 71--84. Berlin, Heidelberg, Springer Verlag, (November 2007)
E. Guy. Proceedings of ATIT 2004, The First International Workshop on Activity Theory Based Practical Methods for IT Design, page 33-48. Copenhagen, Denmark, Published as DAIMI report, University of Aarhus, (2004)