@article{RLIN_1992_9_3_2_a4,
     author = {Salvatore, Addolorata},
     title = {Multiple periodic solutions for {Hamiltonian} systems with singular potential},
     journal = {Atti della Accademia nazionale dei Lincei. Rendiconti Lincei. Matematica e applicazioni},
     pages = {111--119},
     publisher = {mathdoc},
     volume = {Ser. 9, 3},
     number = {2},
     year = {1992},
     zbl = {0763.34034},
     mrnumber = {932787},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RLIN_1992_9_3_2_a4/}
}