@article{SM_1982_43_3_a4,
     author = {Yu. A. Medvedev},
     title = {Cross varieties of algebras},
     journal = {Sbornik. Mathematics},
     pages = {347--376},
     publisher = {mathdoc},
     volume = {43},
     number = {3},
     year = {1982},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1982_43_3_a4/}
}