@article{AL_1973_12_4_a2,
     author = {G. N. Kobzev},
     title = {btt-reducibility.~II},
     journal = {Algebra i logika},
     pages = {433--444},
     publisher = {mathdoc},
     volume = {12},
     number = {4},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1973_12_4_a2/}
}