@article{ZNSL_1981_105_a5,
     author = {L. M. Kogan-Bernstein},
     title = {Simplification of {Gentzen's} reductions in the classical arithmetic},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {45--52},
     publisher = {mathdoc},
     volume = {105},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1981_105_a5/}
}