@article{AL_1979_18_4_a3,
     author = {G. N. Kobzev},
     title = {tt-degrees of recursively enumerable {Turing} {degrees.~II}},
     journal = {Algebra i logika},
     pages = {415--425},
     publisher = {mathdoc},
     volume = {18},
     number = {4},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1979_18_4_a3/}
}