Gunes B, Cakir M. A fitted approximate method for solving singularly perturbed Volterra–Fredholm integro-differential equations with an integral boundary condition. Ukr. Mat. Zhurn. [Internet]. 2024 Feb. 2 [cited 2025 Apr. 4];76(1):115-31. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/7331