@article{MZ_1939__44_168809,
     author = {R., Baldus},
     title = {\"Uber nicht beweisbare und doch entbehrliche {Axiome}},
     journal = {Mathematische Zeitschrift},
     pages = {321--329},
     publisher = {mathdoc},
     volume = {44},
     year = {1939},
     zbl = {0022.07202},
     url = {http://geodesic.mathdoc.fr/item/MZ_1939__44_168809/}
}