@article{1093893709,
author = {Zeman, J. Jay},
title = {Modal systems in which necessity is ``factorable''.},
journal = {Notre Dame J. Formal Logic},
volume = {10},
number = {1},
year = {1969},
pages = { 247-256},
language = {en},
url = {http://dml.mathdoc.fr/item/1093893709}
}
Zeman, J. Jay. Modal systems in which necessity is ``factorable''.. Notre Dame J. Formal Logic, Tome 10 (1969) no. 1, pp. 247-256. http://gdmltest.u-ga.fr/item/1093893709/