@article{AL_1994_33_2_a2,
     author = {M. Kummer and S. Wehner and X.-D. Yi},
     title = {Discrete families of recursive functions, and index sets},
     journal = {Algebra i logika},
     pages = {147--165},
     publisher = {mathdoc},
     volume = {33},
     number = {2},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1994_33_2_a2/}
}