@article{IM2_1971_5_6_a11,
     author = {S. A. Ashmanov and M. A. Bronshtein},
     title = {Simple polyverbal operations},
     journal = {Izvestiya. Mathematics},
     pages = {1418--1436},
     year = {1971},
     volume = {5},
     number = {6},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1971_5_6_a11/}
}