@article{CC_2007_36_4_a8,
     author = {Kontak, Marcin and Szmidt, Janusz},
     title = {Nonlinearity of the round function},
     journal = {Control and Cybernetics},
     pages = {1037--1044},
     publisher = {mathdoc},
     volume = {36},
     number = {4},
     year = {2007},
     zbl = {1244.94033},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CC_2007_36_4_a8/}
}