@article{AL_1995_34_6_a4,
     author = {S. T. Fedoryaev},
     title = {Recursively incompatible algorithmic problems on},
     journal = {Algebra i logika},
     pages = {667--680},
     year = {1995},
     volume = {34},
     number = {6},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1995_34_6_a4/}
}