Dvornyk, A. V., et al. “Almost Periodic Solutions of Lotka – Volterra Systems With Diffusion and Impulsive Action”. Ukrains’kyi Matematychnyi Zhurnal, vol. 70, no. 2, Feb. 2018, pp. 177-92, https://umj.imath.kiev.ua/index.php/umj/article/view/1549.