Zhu, Hui, Jing Niu, Ruimin Zhang, and Yingzhen Lin. “A New Approach for Solving Nonlinear Singular Boundary Value Problems”. Mathematical Modelling and Analysis 23, no. 1 (February 20, 2018): 33-43. Accessed November 5, 2024. https://jau.vgtu.lt/index.php/MMA/article/view/225.