%0 Journal Article %A Avery, Richard I. %A Davis, John M. %A Henderson, Johnny %T Three symmetric positive solutions for Lidstone problems by a generalization of the Leggett-Williams theorem %J Electronic Journal of Differential Equations %D 2000 %V 2000 %I mathdoc %U http://geodesic.mathdoc.fr/item/EJDE_2000__2000__a56/ %G en %F EJDE_2000__2000__a56