%0 Journal Article %A Calábek, Pavel %T A four-point problem for second-order differential systems %J Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica %D 1994 %P 7-15 %V 33 %N 1 %U http://geodesic.mathdoc.fr/item/AUPO_1994_33_1_a0/ %G en %F AUPO_1994_33_1_a0