@article{MZM_1986_40_6_a0,
     author = {A. A. Boyarkin},
     title = {Extensions of $PI$-algebras},
     journal = {Matemati\v{c}eskie zametki},
     pages = {705--712},
     publisher = {mathdoc},
     volume = {40},
     number = {6},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1986_40_6_a0/}
}