@article{DA_2002_9_4_a5,
     author = {D. Yu. Cherukhin},
     title = {On invariant classes of functions that are repetition-free expressible by formulas},
     journal = {Diskretnyj analiz i issledovanie operacij},
     pages = {57--74},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {2002},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DA_2002_9_4_a5/}
}