Lu, Zhiqi; Lü, Jianfeng Periodic solutions of a predator-prey model with two delays. (Chinese. English summary) Zbl 1240.34413 J. Nanjing Norm. Univ., Nat. Sci. Ed. 33, No. 2, 6-12 (2010). Summary: A food chain system with ratio-dependent Holling II functional response and two periodic delays is studied. Using the coincidence degree theory, the existence of periodic solutions for this model is obtained under suitable conditions. MSC: 34K60 Qualitative investigation and simulation of models involving functional-differential equations 34K13 Periodic solutions to functional-differential equations 47N20 Applications of operator theory to differential and integral equations 92D40 Ecology Keywords:periodic delay; coincidence degree theory; periodic solution PDFBibTeX XMLCite \textit{Z. Lu} and \textit{J. Lü}, J. Nanjing Norm. Univ., Nat. Sci. Ed. 33, No. 2, 6--12 (2010; Zbl 1240.34413)