@article{RSMUP_1991__85__201_0, author = {Bessi, Ugo}, title = {Multiple closed orbits for singular conservative systems via geodesic theory}, journal = {Rendiconti del Seminario Matematico della Universit\`a di Padova}, pages = {201--215}, publisher = {Seminario Matematico of the University of Padua}, volume = {85}, year = {1991}, zbl = {0850.70210}, mrnumber = {1142541}, language = {en}, url = {http://www.numdam.org/item/RSMUP_1991__85__201_0/} }