@article{AMLG_1981__21_137985,
     author = {Michael v. Rimscha},
     title = {Universality and strong extensionality.},
     journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
     pages = {179--194},
     publisher = {mathdoc},
     volume = {21},
     year = {1981},
     zbl = {0481.03031},
     url = {http://geodesic.mathdoc.fr/item/AMLG_1981__21_137985/}
}