@article{CMUC_1991_32_3_a10,
     author = {Nieto, Juan J.},
     title = {Periodic solutions for third order ordinary differential equations},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     pages = {495--499},
     year = {1991},
     volume = {32},
     number = {3},
     mrnumber = {1159797},
     zbl = {0832.34028},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMUC_1991_32_3_a10/}
}