1.
Zavizion GV, ShkiI NI. Systems of singularly perturbed degenerate integro-differential equations. Ukr. Mat. Zhurn. [Internet]. 1999Dec.25 [cited 2024Nov.22];51(12):1694–1703. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/4772