@article{AL_1994_33_2_a3,
     author = {S. I. Mardaev},
     title = {Convergence of positive schemes in ${\rm S}4$ and ${\rm},
     journal = {Algebra i logika},
     pages = {166--178},
     publisher = {mathdoc},
     volume = {33},
     number = {2},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1994_33_2_a3/}
}