@article{MV_1968_20_2_a1,
     author = {A. U\v{s}an},
     title = {Odno opredelenie gruppy i ee obobshchenie na n-arnij slu\v{c}aj},
     journal = {Matemati\v{c}ki vesnik},
     pages = {145 },
     publisher = {mathdoc},
     volume = {20},
     number = {2},
     year = {1968},
     url = {http://geodesic.mathdoc.fr/item/MV_1968_20_2_a1/}
}