@article{AL_1976_15_3_a0,
     author = {A. N. Degtev},
     title = {Partially ordered sets of $1$-degrees that occur in recursively},
     journal = {Algebra i logika},
     pages = {249--266},
     publisher = {mathdoc},
     volume = {15},
     number = {3},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1976_15_3_a0/}
}