@article{GDZPPN002043750,
title = {Decision procedures for S3... and S4.. .},
journal = {Archiv f\"ur mathematische Logik und Grundlagenforschung},
volume = {12},
year = {1969},
pages = {155-158},
url = {http://dml.mathdoc.fr/item/GDZPPN002043750}
}
Zeman, J. Jay. Decision procedures for S3... and S4.. .. Archiv für mathematische Logik und Grundlagenforschung, Tome 12 (1969) pp. 155-158. http://gdmltest.u-ga.fr/item/GDZPPN002043750/