| [1] Li Y K, Kuang, Y. Periodic solutions of periodic delay Lotka-Volterra equations and systems. J Math Anal Appl, 2001, 255: 260--280
[2] Ye D, et al. Periodic solutions for scalar functional differential equations. Nonlinear Anal, 2005, 62: 1157--1181
[3] Teng Z, Yu Y. Some new results of nonautonomous Lotka-Volterra competitive system with delay. J Math Anal Appl, 2000, 241: 254--275
[4] Freedmand H I, Wu J H. Periodic solutions of single-species models with periodic delay. SIAM J Math Anal, 1992, 23: 689--701
[5] Fan M, Wang K. Optimal harvesting policy for single population with periodic coefficients. Math Biosci, 1998, 152(2): 165--177
[6] Jiang D Q, Wei J J. Existence of positive periodic solutions for Volterra intergo-differential equations. Acta Math Sincia B, 2001, 21(4): 553--560
[7] Yang X, Chen L. Periodic solution of single species nonautomous diffusion models with continuous time delay. Math Comput Modell, 1996, 23: 469--493
[8] Chen F D. Permanence of a single species discrete model with feedback control and delay. Appl Math Lett, 2007, 20(7): 729--733
[9] Lu Z, Takeuchi Y. Global asymptotic behaviour in single-species discrete diffusion systems. J Math Biol, 1993, 32: 67--77
[10] Cui J, et al. Permance and extinction for dispersal population systems. J Math Anal Appl, 2004, 298: 73--93
[11] Li Y K. Existence and global attractivity of positive periodic solutions for a class of delay differential equations. Chinese Sci (Ser A), 1998, 28(2): 108--118
[12] Wang A Y, Jiang D Q. Existence of positive periodic solutions for functional differential equations. Kyush J Math, 2002, 56: 193--202
[13] Krasnoselskii M A. Positive Solutions of Operator Equations. Gorninggen: Noordhoff, 1964
[14] Liu B W, Huang L H. Existence and uniqueness of periodic solutions for a kind of first order neutral functional differential equations. J Math Anal Appl, 2006, 322: 121--132
[15] Lu S P. On the existence of positive periodic solutions for neutral functional differential equation with multiple deviating arguments. J Math
Anal Appl, 2003, 280: 321--333 |