[1] Laddle G S, Lakshmikantham V, Vatala A S. Monotone iterative technique for nonlinear differential
equations. Bostone: Pitman Advance Publishing Program, 1985
[2] Cabada A, Nieto J J. Extremal solutions of second order nonlinear periodic boundary value problems.
Appl Math Comput, 1990, 40: 135-145
[3] Cabada A. The method of lower and upper solutions for second, third, fourth and higher order boundary
value problem. J Math Anal Appl, 1994, 185: 302-320
[4] Liu Y S, Qi J G. The boundary value problem for discontinuous nonlinear second order differential equa-
tions. J Engineering Mathematics, 1998, 15(2): 72-78 (in Chinese)
[5] Lakshmikantham V, Nieto J J, Sun Y. An existence result about periodic boundary value problems of
second order differential equations. Appl Anal, 1990, 40: 1-10
[6] Wang J Y, Jiang D Q. A singular nonlinear second-order periodic boundary value problem. J Tohoku
Math, 1998, 50: 203-210
[7] Kong L, Wang S, Wang J. Positive solution of a singular nonlinear third-order periodic boundary value
problem. J Comput Appl Math, 2001, 132: 247-253
[8] Guo Dajun, Lakshmikantham V. Nonlinear problems in abstract cones. New York: Academic Press Inc,
1988
[9] Nussbaum R D. Eigenvectors of nonlinear positive operators and the linear Krein-Rutman theorem. In:
Fixed Point Theory, LNM 886. New York, Berlin: Springer-Verlag, 1980. 309-330 |