Pelen , N.N. 2021. On the dynamics of the impulsive predator-prey systems with Beddington – DeAngelis type functional response. Ukrains’kyi Matematychnyi Zhurnal. 73, 4 (Apr. 2021), 523 - 543. DOI:https://doi.org/10.37863/umzh.v73i4.619.