@article{ARM_1980__16_3_a0,
     author = {Bartu\v{s}ek, Miroslav},
     title = {Monotonicity theorems for second order non-linear differential equations},
     journal = {Archivum mathematicum},
     pages = {127--135},
     publisher = {mathdoc},
     volume = {16},
     number = {3},
     year = {1980},
     mrnumber = {594458},
     zbl = {0448.34041},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ARM_1980__16_3_a0/}
}