DavydovV. F. “Majorant Estimates for Solutions of Quadratic Difference Systems With Lag”. Ukrains’kyi Matematychnyi Zhurnal 47, no. 4 (April 25, 1995): 542–545. Accessed November 24, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/5454.