@article{VYURU_2015_8_1_a8,
     author = {S. M. Ratseev},
     title = {Some generalizations of {Shannon's} theory of perfect ciphers},
     journal = {Vestnik \^U\v{z}no-Uralʹskogo gosudarstvennogo universiteta. Seri\^a, Matemati\v{c}eskoe modelirovanie i programmirovanie},
     pages = {111--127},
     publisher = {mathdoc},
     volume = {8},
     number = {1},
     year = {2015},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VYURU_2015_8_1_a8/}
}