@article{DAN_1973_213_4_a4,
     author = {A. P. Kombarov and V. I. Malykhin},
     title = {On $\Sigma$-products},
     journal = {Doklady Akademii Nauk},
     pages = {774--776},
     publisher = {mathdoc},
     volume = {213},
     number = {4},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_213_4_a4/}
}