@article{10_4064_fm_48_1_59_69,
     author = {H. Rasiowa and Roman Sikorski},
     title = {On the {Gentzen} theorem},
     journal = {Fundamenta Mathematicae},
     pages = {59--69},
     publisher = {mathdoc},
     volume = {48},
     number = {1},
     year = {1959},
     doi = {10.4064/fm-48-1-59-69},
     language = {de},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/fm-48-1-59-69/}
}