@article{1093888014, author = {Facione, Peter A.}, title = {The entailment operator.}, journal = {Notre Dame J. Formal Logic}, volume = {18}, number = {1}, year = {1977}, pages = { 415-420}, language = {en}, url = {http://dml.mathdoc.fr/item/1093888014} }
Facione, Peter A. The entailment operator.. Notre Dame J. Formal Logic, Tome 18 (1977) no. 1, pp. 415-420. http://gdmltest.u-ga.fr/item/1093888014/