@article{1154698578, author = {Medeiros, Maria da Paz N.}, title = {A new S4 classical modal logic in natural deduction}, journal = {J. Symbolic Logic}, volume = {71}, number = {1}, year = {2006}, pages = { 799-809}, language = {en}, url = {http://dml.mathdoc.fr/item/1154698578} }
Medeiros, Maria da Paz N. A new S4 classical modal logic in natural deduction. J. Symbolic Logic, Tome 71 (2006) no. 1, pp. 799-809. http://gdmltest.u-ga.fr/item/1154698578/