@article{1093882657, author = {Dumitriu, Anton}, title = {Necessary and contingent deduction.}, journal = {Notre Dame J. Formal Logic}, volume = {20}, number = {1}, year = {1979}, pages = { 525-534}, language = {en}, url = {http://dml.mathdoc.fr/item/1093882657} }
Dumitriu, Anton. Necessary and contingent deduction.. Notre Dame J. Formal Logic, Tome 20 (1979) no. 1, pp. 525-534. http://gdmltest.u-ga.fr/item/1093882657/