@article{PMFA_1986_31_4_a6,
     author = {Jelen, Josef},
     title = {Fyzika a matematika v {Etiopii}},
     journal = {Pokroky matematiky, fyziky a astronomie},
     pages = {224--229},
     year = {1986},
     volume = {31},
     number = {4},
     language = {cs},
     url = {http://geodesic.mathdoc.fr/item/PMFA_1986_31_4_a6/}
}