@article{ZNSL_1974_40_a17,
     author = {N. A. Shanin},
     title = {On a~hierarchy of {Brouwer} constructive functionals},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {142--147},
     year = {1974},
     volume = {40},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1974_40_a17/}
}