@article{ARM_1977__13_4_a2,
     author = {Mehri, B.},
     title = {A note on periodic solution of second order non-linear differential equations},
     journal = {Archivum mathematicum},
     pages = {191--194},
     publisher = {mathdoc},
     volume = {13},
     number = {4},
     year = {1977},
     mrnumber = {0477244},
     zbl = {0394.34034},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1977__13_4_a2/}
}