%0 Journal Article %A Andrzej Szulkin %T An Index Theory and Existence of Multiple Brake Orbits for Star-Shaped Hamiltonian Systems %J Mathematische Annalen %D 1989 %P 241-256 %V 283 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/MAN_1989__283_1_164506/ %F MAN_1989__283_1_164506