@article{SM_1993_74_1_a6,
     author = {V. M. Shyrayev},
     title = {Finite filtering semigroups},
     journal = {Sbornik. Mathematics},
     pages = {79--99},
     publisher = {mathdoc},
     volume = {74},
     number = {1},
     year = {1993},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1993_74_1_a6/}
}