@article{PDM_2014_1_a4,
     author = {G. I. Shushuev},
     title = {Finding the optimal linear approximation of {Feistel} network},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {40--54},
     publisher = {mathdoc},
     number = {1},
     year = {2014},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2014_1_a4/}
}