@article{MMO_2012_73_1_a1,
     author = {V. A. Kleptsyn and D. A. Filimonov},
     title = {Lyapunov exponents and other properties of $N$-groups},
     journal = {Trudy Moskovskogo matemati\v{c}eskogo ob\^{s}estva},
     pages = {37--46},
     publisher = {mathdoc},
     volume = {73},
     number = {1},
     year = {2012},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MMO_2012_73_1_a1/}
}