Klevchuk, I.I. (2002) “Homoclinic Points for a Singularly Perturbed System of Differential Equations with Delay”, Ukrains’kyi Matematychnyi Zhurnal, 54(4), pp. 563–567. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4093 (Accessed: 5 December 2025).