@article{1093888408, author = {Ulrich, Dolph}, title = {Semantics for ${\rm S}4.1.2$.}, journal = {Notre Dame J. Formal Logic}, volume = {19}, number = {1}, year = {1978}, pages = { 461-464}, language = {en}, url = {http://dml.mathdoc.fr/item/1093888408} }
Ulrich, Dolph. Semantics for ${\rm S}4.1.2$.. Notre Dame J. Formal Logic, Tome 19 (1978) no. 1, pp. 461-464. http://gdmltest.u-ga.fr/item/1093888408/