@article{1183730569, author = {Henkin, Leon}, title = {Fragments of the Propositional Calculus}, journal = {J. Symbolic Logic}, volume = {14}, number = {1}, year = {1949}, pages = { 42-48}, language = {en}, url = {http://dml.mathdoc.fr/item/1183730569} }
Henkin, Leon. Fragments of the Propositional Calculus. J. Symbolic Logic, Tome 14 (1949) no. 1, pp. 42-48. http://gdmltest.u-ga.fr/item/1183730569/