@article{SM_1973_21_3_a3,
     author = {L. M. Gluskin and L. N. \`El'kin},
     title = {Positional operatives with invertible elements},
     journal = {Sbornik. Mathematics},
     pages = {412--422},
     publisher = {mathdoc},
     volume = {21},
     number = {3},
     year = {1973},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1973_21_3_a3/}
}