Aripov, M.M., et al. “On the Behavior of Solutions of a Doubly Nonlinear Degenerate Parabolic System With Nonlinear Sources and Absorptions With Variable Densities”. Bulletin of the Karaganda University. Mathematics Series, vol. 117, no. 1, Mar. 2025, pp. 12-23, doi:10.31489/2025m1/12-23.