KlevchukI. I. “Bifurcation of an Equilibrium State of a Singularly Perturbed System With Lag”. Ukrains’kyi Matematychnyi Zhurnal 47, no. 8 (August 25, 1995): 1022–1028. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5499.