Kang, Joon Hyuk. “Perturbation of A Nonlinear Elliptic Biological Interacting Model With Multiple Species”. Communications in Mathematics and Applications 2, no. 2-3 (December 28, 2011): 61–76. Accessed May 6, 2024. http://www.rgnpublications.com/journals/index.php/cma/article/view/132.