Khan, Arshad, Sucheta Nayak, and R. K. Mohanty. 2018. “OFF-STEP DISCRETIZATION FOR SYSTEM OF NONLINEAR SINGULAR BOUNDARY VALUE PROBLEMS USING VARIABLE MESH”. Italian Journal of Pure and Applied Mathematics 39 (February):508-29. https://journals.uniurb.it/index.php/ijpam/article/view/6888.