@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/