@article{10_21136_AM_1973_103446,
     author = {Kop\'a\v{c}kov\'a, Marie},
     title = {On periodic solutions of some equations of mathematical physics},
     journal = {Applications of Mathematics},
     pages = {33--42},
     publisher = {mathdoc},
     volume = {18},
     number = {1},
     year = {1973},
     doi = {10.21136/AM.1973.103446},
     mrnumber = {0312044},
     zbl = {0249.35057},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/AM.1973.103446/}
}