Dishlieva, Katya, and Katya Dishlieva. “PERIODIC SOLUTIONS OF A MODEL OF LOTKA-VOLTERRA WITH VARIABLE STRUCTURE AND IMPULSES”. JOURNAL OF ADVANCES IN MATHEMATICS 11, no. 6 (October 26, 2015): 5317–5325. Accessed July 22, 2024. https://rajpub.com/index.php/jam/article/view/1228.