TY - JOUR AU - Benci, V. TI - Closed geodesics for the Jacobi metric and periodic solutions of prescribed energy of natural hamiltonian systems JO - Annales de l'I.H.P. Analyse non linéaire PY - 1984 SP - 401 EP - 412 VL - 1 IS - 5 PB - Gauthier-Villars UR - http://www.numdam.org/item/AIHPC_1984__1_5_401_0/ LA - en ID - AIHPC_1984__1_5_401_0 ER -