@article{1183734847, author = {Aqvist, Lennart}, title = {Results Concerning Some Modal Systems That Contain S2}, journal = {J. Symbolic Logic}, volume = {29}, number = {1}, year = {1964}, pages = { 79-87}, language = {en}, url = {http://dml.mathdoc.fr/item/1183734847} }
Aqvist, Lennart. Results Concerning Some Modal Systems That Contain S2. J. Symbolic Logic, Tome 29 (1964) no. 1, pp. 79-87. http://gdmltest.u-ga.fr/item/1183734847/