@article{AL_1974_13_4_a1,
     author = {Yu. L. Ershov},
     title = {Maximal and everywhere defined functionals},
     journal = {Algebra i logika},
     pages = {374--397},
     publisher = {mathdoc},
     volume = {13},
     number = {4},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1974_13_4_a1/}
}