1.
Perestyuk NA, Slyusarchuk VY. Green–Samoilenko operator in the theory of invariant sets of nonlinear differential equations. Ukr. Mat. Zhurn. [Internet]. 2009Jul.25 [cited 2024Nov.24];61(7):948-57. Available from: https://umj.imath.kiev.ua/index.php/umj/article/view/3069