@article{10_21136_MB_1992_126060,
     author = {Stan\v{e}k, Svatoslav},
     title = {Periodic solutions of nonlinear second-order differential equations with parameter},
     journal = {Mathematica Bohemica},
     pages = {337--348},
     publisher = {mathdoc},
     volume = {117},
     number = {4},
     year = {1992},
     doi = {10.21136/MB.1992.126060},
     mrnumber = {1197284},
     zbl = {0771.34034},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/MB.1992.126060/}
}