@article{AMLG_1954__2_137721,
     author = {Paul Lorenzen},
     title = {Zur {Begr\"undung} der {Modallogik.}},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {15--28},
     publisher = {mathdoc},
     volume = {2},
     year = {1954},
     zbl = {0058.24603},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1954__2_137721/}
}