@article{10_21136_CMJ_1990_102388,
     author = {Andres, J\'an},
     title = {Periodic derivative of solutions to nonlinear differential equations},
     journal = {Czechoslovak Mathematical Journal},
     pages = {353--360},
     publisher = {mathdoc},
     volume = {40},
     number = {3},
     year = {1990},
     doi = {10.21136/CMJ.1990.102388},
     mrnumber = {1065015},
     zbl = {0727.34029},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1990.102388/}
}