@article{10_21136_AM_1973_103474,
     author = {Matas, Vladim{\'\i}r},
     title = {On non-existence of periodic solutions of an important differential equation},
     journal = {Applications of Mathematics},
     pages = {213--226},
     publisher = {mathdoc},
     volume = {18},
     number = {4},
     year = {1973},
     doi = {10.21136/AM.1973.103474},
     mrnumber = {0320443},
     zbl = {0268.34048},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/AM.1973.103474/}
}