@article{EJDE_2001__2001__a147,
     author = {Furi,  Massimo and Pera,  Maria Patrizia and Spadini,  Marco},
     title = {Multiplicity of forced oscillations for scalar differential equations},
     journal = {Electronic journal of differential equations},
     year = {2001},
     volume = {2001},
     zbl = {0979.34035},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2001__2001__a147/}
}