@article{1094068849,
author = {Thomas, Ivo},
title = {A theorem on ${\rm S}4.2$ and ${\rm S}4.4$.},
journal = {Notre Dame J. Formal Logic},
volume = {8},
number = {3},
year = {1967},
pages = { 335-336},
language = {en},
url = {http://dml.mathdoc.fr/item/1094068849}
}
Thomas, Ivo. A theorem on ${\rm S}4.2$ and ${\rm S}4.4$.. Notre Dame J. Formal Logic, Tome 8 (1967) no. 3, pp. 335-336. http://gdmltest.u-ga.fr/item/1094068849/