@article{IM2_1967_1_3_a7,
     author = {M. A. Bronshtein},
     title = {On polynilpotent products of groups},
     journal = {Izvestiya. Mathematics},
     pages = {651--666},
     year = {1967},
     volume = {1},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1967_1_3_a7/}
}