@article{1183732820, author = {Hiz, H.}, title = {Inferential Equivalence and Natural Deduction}, journal = {J. Symbolic Logic}, volume = {22}, number = {1}, year = {1957}, pages = { 237-240}, language = {en}, url = {http://dml.mathdoc.fr/item/1183732820} }
Hiz, H. Inferential Equivalence and Natural Deduction. J. Symbolic Logic, Tome 22 (1957) no. 1, pp. 237-240. http://gdmltest.u-ga.fr/item/1183732820/