@article{SM_1992_73_2_a12,
     author = {S. V. Rychkov},
     title = {On verbal factors of almost free groups in varieties},
     journal = {Sbornik. Mathematics},
     pages = {501--516},
     year = {1992},
     volume = {73},
     number = {2},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1992_73_2_a12/}
}