@article{AMLG_1965__8_137782,
     author = {Herbert Fiedler},
     title = {Zur {Stufenreduktion} von {Kalk\"ulen.}},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {63--103},
     publisher = {mathdoc},
     volume = {8},
     year = {1965},
     zbl = {0158.24701},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1965__8_137782/}
}