@article{AL_1986_25_5_a4,
     author = {A. S. Morozov},
     title = {On a problem of {Bergstra} and {Tiuryn}},
     journal = {Algebra i logika},
     pages = {566--583},
     publisher = {mathdoc},
     volume = {25},
     number = {5},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1986_25_5_a4/}
}