@article{RM_1987_42_6_a11,
     author = {A. A. Boyarkin},
     title = {Relations for extensions in varieties of algebras},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {229--230},
     publisher = {mathdoc},
     volume = {42},
     number = {6},
     year = {1987},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1987_42_6_a11/}
}