1Agarwal R P and O'Regan D. Singular boundary value problemes. Nonlinear Analysis, 1996, 27:645-656.
2Agarwal R P and O'Regan D. Nonlinear superlinear singular and nonsingular second order boundary value problems. J. Diff. Eans., 1998, 143: 60-95.
3Guo Dajun, Lakshmikansham V and Liu Xinzhi. Nonlinear Integral Equations in Abstract Spaces.Kluwer Academic Publishers, Dordrecht, 1996.
4liu lishan. Iterative method for solution and coupled quasi-solutions of nonlinear Fredholm integral equations in ordered Banach spaces. Indian J. pure Appl. Math., 1996, 27(10): 959-972.
5AGARWAL R P, O' REGAN D. Multiple nonnegative solutions for second order impulsive differential equations [J]. Appl Math Comput, 2000,114 : 51-59.
6GUO D J. Existence of solutions of Boundary Value Problems for nonlinear second order impulsive differential equations in Banach spaces [J]. Jour Math Anal Appl,1994,181:407-421.