E. Dashofy, A. van der Hoek, и R. Taylor. Proceedings of the 24rd International Conference on Software Engineering, 2002. ICSE 2002, стр. 266--276. IEEE, (мая 2002)
E. Gourova, K. Ducatel, J. Gavigan, F. Scapolo, и P. Pietrogiacomo. (1101 2001)NT: Produced by the European Commission, Joint Research Centre. Study carried out by the Institute for Prospective Technological Studies.; LV: Available online; EM: 2004.