@article{PMFA_1956__1_2_a1,
     author = {Alpert, J. L.},
     title = {Ionosf\'era},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {145--155},
     publisher = {mathdoc},
     volume = {01},
     number = {2},
     year = {1956},
     language = {cz},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1956__1_2_a1/}
}