DvornykA. V., and TkachenkoV. I. “Frequency Locking of Periodic Solutions to Differential Equations With Impulsive Perturbations”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 74, no. 7, Aug. 2022, pp. 939 -60, doi:10.37863/umzh.v74i7.7138.