%0 Journal Article %A Ma, Ruyun %A Chen, Ruipeng %T Existence of one-signed solutions of nonlinear four-point boundary value problems %J Czechoslovak Mathematical Journal %D 2012 %P 593-612 %V 62 %N 3 %I mathdoc %U https://geodesic-test.mathdoc.fr/articles/10.1007/s10587-012-0052-3/ %R 10.1007/s10587-012-0052-3 %G en %F 10_1007_s10587_012_0052_3