@article{1183732392, author = {Montague, Richard and Henkin, Leon}, title = {On the Definition of `Formal Deduction'}, journal = {J. Symbolic Logic}, volume = {21}, number = {1}, year = {1956}, pages = { 129-136}, language = {en}, url = {http://dml.mathdoc.fr/item/1183732392} }
Montague, Richard; Henkin, Leon. On the Definition of `Formal Deduction'. J. Symbolic Logic, Tome 21 (1956) no. 1, pp. 129-136. http://gdmltest.u-ga.fr/item/1183732392/