ValeyevK. G., & DzhalladovaI. A. (2003). Derivation of Moment Equations for Solutions of a System of Nonlinear Difference Equations Dependent on a Semi-Markov Process. Ukrains’kyi Matematychnyi Zhurnal, 55(6), 858-864. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/3960