1. Three symmetric positive solutions for a second-order boundary value problem;Avery;Appl. Math. Lett.,2000
2. J. Henderson and H.B. Thompson, Multiple symmetric positive solutions for a second order boundary value problem, Proceedings American Mathematical Society.
3. J. Henderson and H.B. Thompson, Existence of multiple solutions for second order boundary value problems, J. Differential Equations.
4. Multiple positive solutions for higher order boundary value problems;Kaufmann;Rocky Mountain J. Math.,1998