@article{AL_2014_53_5_a4,
     author = {A. I. Stukachev},
     title = {Properties of $s\Sigma$-reducibility},
     journal = {Algebra i logika},
     pages = {625--642},
     year = {2014},
     volume = {53},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2014_53_5_a4/}
}