@article{ND_2013_9_4_a2,
     author = {P. V. Markov},
     title = {Group classification of discrete dynamical systems},
     journal = {Russian journal of nonlinear dynamics},
     pages = {641--650},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {2013},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ND_2013_9_4_a2/}
}