1. ITU-T Recommendation Z.100: Specification and description language (SDL), 1999.
2. ITU-T Recommendation Z.120: Message Sequence Chart (MSC), 1999.
3. ITU-T MSC2000R3 Draft Z.120: Message Sequence Charts ITU-T Recommendation Z.120, 1999.
4. Terekhov, A.N. et al., RTST++: Methodology and a CASE Tool for the Development of Information Systems and Software For Real-Time Systems, Programmirovanie, 1999, no. 5, pp. 45–51 [Programming and Computer Software (Engl. Transl.), 1999, no. 5, pp. 276–281].
5. Rumbaugh, J., Jacobson, I., and Booch, G., The Unified Modeling Language Reference Manual, Reading, Mass.: Addison-Wesley, 1999.