@article{SM_1972_16_3_a5,
     author = {S. V. Polin},
     title = {Free decompositions in varieties of $\Lambda$-groups},
     journal = {Sbornik. Mathematics},
     pages = {389--407},
     year = {1972},
     volume = {16},
     number = {3},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1972_16_3_a5/}
}