Shishkin, Grigorii. “Grid Approximation of Singularly Perturbed Parabolic reaction‐diffusion Equations With Piecewise Smooth initial‐boundary Conditions”. Mathematical Modelling and Analysis 12, no. 2 (June 30, 2007): 235-254. Accessed December 22, 2024. https://journals.vilniustech.lt/index.php/MMA/article/view/7125.