@article{1183732842, author = {Bernays, Paul}, title = {Review: Irving M. Copi, Another Variant of Natural Deduction}, journal = {J. Symbolic Logic}, volume = {22}, number = {1}, year = {1957}, pages = { 298-299}, language = {en}, url = {http://dml.mathdoc.fr/item/1183732842} }
Bernays, Paul. Review: Irving M. Copi, Another Variant of Natural Deduction. J. Symbolic Logic, Tome 22 (1957) no. 1, pp. 298-299. http://gdmltest.u-ga.fr/item/1183732842/