@article{AL_1988_27_4_a5,
     author = {V. L. Selivanov},
     title = {Ershov's hierarchy and $\rm T$-jumps},
     journal = {Algebra i logika},
     pages = {464--478},
     publisher = {mathdoc},
     volume = {27},
     number = {4},
     year = {1988},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1988_27_4_a5/}
}