@article{1093894297,
author = {Schumm, G. F.},
title = {Solutions to four modal problems of Soboci\'nski.},
journal = {Notre Dame J. Formal Logic},
volume = {12},
number = {1},
year = {1971},
pages = { 335-340},
language = {en},
url = {http://dml.mathdoc.fr/item/1093894297}
}
Schumm, G. F. Solutions to four modal problems of Sobociński.. Notre Dame J. Formal Logic, Tome 12 (1971) no. 1, pp. 335-340. http://gdmltest.u-ga.fr/item/1093894297/