Oliynyk, A.P., and L.O. Shtayer. “The Dirichlet Problem Successive Upper Relaxation Numerical Method Convergence Relaxation Parameters Influence Investigations”. Carpathian Mathematical Publications, vol. 4, no. 2, Dec. 2012, pp. 289-96, https://scijournals.pnu.edu.ua/index.php/cmp/article/view/2274.