参考文献/References:
[1] 田秀华, 聂清凯, 夏健明. 商业生态系统视角下企业互动关系模型构建研究 [J]. 南方经济, 2006(4):50-57.doi:10.1016/j.ica.2010.01.015.
[2] XU Rui, CHEN Lan-sun, HAO Fei-long. Periodic solution of a discrete time Lotka-Volterra type food-chain model with delays [J]. Applied Mathematics and Computation, 2005(1):91-103.
[3] ZHANG Ke-jun, WEN Zhao-hui. Dynamics of a discrete three species food chain system [J]. Int J Comput Math Sci, 2011(1):13-15.
[4] ZHANG R Y, CHEN Y, WU J. Periodic solutions of a single species discrete population model with periodic harvest/stock [J]. Computers and Mathematics with Applications, 2000, (1/2):77-90.
[5] ZHANG Wei-ping, ZHU De-ming, BI Ping. Multiple positive periodic solutions of a delayed discrete predator-prey system with type Ⅳ functional responses [J]. Applied Mathematics Letters, 2007, (10):1031-1038.doi:10.1016/j.aml.2006.11.005.
[6] FAN Meng, WANG Ke. Periodic solutions of a discrete time nonautonomous ratio-dependent predator-prey system [J]. Mathematical and Computer Modelling, 2002, (9/10):951-961.
[7] WIENER J. Differential equations with piecewise constant delays [A]. New York:crc Press, 1984.
[8] GAINES R E, MAWHIN J L. Coincidence degree and nonlinear differential equations [M]. New York:springer-verlag, 1997.