[1] Ladde G S, Lakshmikantham V, Vatsala. Monotone Iterative Techniques of Nonlinear Differential Equations[M]. Boston: Pitman Publishing Inc,1985. [2] Kaul S K, Vatsla A S. Monotone method for integrodifferential equations with periodic boundary conditions[J].Appl Anal,1986,21(4):297~305. [3] Hu Shouchuan, Lakshmikantham V. Periodic boundary value problems for integrodifferential equations of Volterra type[J].Nonlinear Anal,1986,10(11):1203~1208. [4] Cabada A. The monotone method for first-order problems with linear and nonlinear boundary conditins[J].Appl Math Comp,1994,151(1):163~186. [5] Cheng Yubo, Zhuang Wan. On monotone iterative method for periodic boundary value problems of nonlinear integrodifferential equations[J].Nonlinear Anal,1994,22(3):295~303. [6] Nkashama M N. A generalization upper and lower solutions methods and multiplicity results for nonlinear first-order ODEs[J].J Math Anal Appl,1998,140(2):381~395. [7] Erbe L H, Guo Dajun. Periodic boundary value problems for second order integrodifferential equations of mixed type[J].Anal Appl,1992,46(4):249~258. [8] Gelbaum B R, Olmsted J M. Counterexamples in Analysis[M]. Holden-Day, Inc, 1964. [9] Gaines R E, Mawhin J L. Coincidence Degree and Nonlinear Differential Equations[M]. Lecture Notes in Math,Vol.568,Berlin,New York:Springer-Verlag,1977. |