1. Booch, G., Rumbaugh, J., Jacobson, I.: The Unified Modeling Language User Guide. Addison–Wesley,1999
2. Constantine, L. L. and Lockwood, L. A. D.: Software for use: a practical guide to the models and methods of usage-centered design, Addison Wesley, Reading, Mass, 1999.
3. Durán, A.: Un Entorno Metodológico de Ingeniería de Requisitos para Sistemas de Información. Doctoral Thesis. University of Sevilla. 2000
4. Greenberg, S.: The 1988 conference on computer-supported cooperative work: Trip report. ACM SIGCHI Bulletin, 21(1), pp. 49–55, July 1989.
5. Greif, I.: Computer-Supported Cooperative Work: A Book of Readings. Morgan Kaufmann, San Mateo CA, 1988