@article{AL_2000_39_5_a2,
     author = {I. Sh. Kalimullin},
     title = {Relative complements in $\Delta_2^0$-degrees with respect to enumerability},
     journal = {Algebra i logika},
     pages = {547--566},
     publisher = {mathdoc},
     volume = {39},
     number = {5},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_2000_39_5_a2/}
}