N. V. Gybkina, S. M. Lamtyugova, and M. V. Sidorov, “TWO-SIDED APPROXIMATIONS METHOD BASED ON THE GREEN’S FUNCTIONS USE FOR CONSTRUCTION OF A POSITIVE SOLUTION OF THE DIRICHLE PROBLEM FOR A SEMILINEAR ELLIPTIC EQUATION ”, RIC, no. 3, pp. 26–41, Oct. 2021.