@article{AL_1975_14_5_a4,
     author = {S. V. Pchelintsev},
     title = {Nilpotency of the associator ideal of a free finitely generated},
     journal = {Algebra i logika},
     pages = {543--571},
     year = {1975},
     volume = {14},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1975_14_5_a4/}
}