@article{MZM_1991_49_3_a24,
     author = {V. \'E. Shpil'rain},
     title = {Some applications of free differential calculus in group theory},
     journal = {Matemati\v{c}eskie zametki},
     pages = {156--157},
     publisher = {mathdoc},
     volume = {49},
     number = {3},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1991_49_3_a24/}
}