@article{MVK_2012_3_3_a4,
     author = {B. A. Pogorelov and M. A. Pudovkina},
     title = {Factor structures of transformations},
     journal = {Matemati\v{c}eskie voprosy kriptografii},
     pages = {81--104},
     year = {2012},
     volume = {3},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MVK_2012_3_3_a4/}
}