Prathap T, Nageshwar Rao R. Exponentially fitted finite difference methods for a singularly perturbed nonlinear differential-difference equation with a small negative shift. M [Internet]. 2025 Jun. 30 [cited 2025 Jul. 10];118(2):189-207. Available from: https://mts.buketov.edu.kz/index.php/mathematics-vestnik/article/view/759