@article{MZ_1935__39_168546,
     author = {G. Gentzen},
     title = {Untersuchungen \"uber das logische {Schlie{\ss}en} {I}},
     journal = {Mathematische Zeitschrift},
     pages = {176--210},
     publisher = {mathdoc},
     volume = {39},
     year = {1935},
     zbl = {0010.14501},
     url = {http://geodesic.mathdoc.fr/item/MZ_1935__39_168546/}
}