The Rocky Mountain Journal of Mathematics
A two-point boundary value problem for a system of first-order ordinary differential equations with impulse effects is studied. The method of upper and lower solutions is employed to obtain the existence of a solution and a method of forced monotonicity is employed to obtain iterative improvement. The main result is illustrated with an application to the Liénard equation with periodic boundary conditions.
Eloe, Paul W. and Henderson, Johnny, "A boundary value problem for a system of ordinary differential equations with impulse effects" (1997). Mathematics Faculty Publications. 121.