@article{AMLG_1970__13_137844,
     author = {Peter H\'ajek},
     title = {Logische {Kategorien.}},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {168--193},
     publisher = {mathdoc},
     volume = {13},
     year = {1970},
     language = {de},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1970__13_137844/}
}