Voir la notice de l'article provenant de la source European Digital Mathematics Library
@article{PORMA_1949__8_2_114675, author = {Halld\'en, S.}, title = {A reduction of the primitive symbols of the {Lewis} calculi}, journal = {Portugaliae mathematica}, pages = {85--88}, publisher = {mathdoc}, volume = {8}, number = {2}, year = {1949}, mrnumber = {0038310}, zbl = {0037.29501}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PORMA_1949__8_2_114675/} }
Halldén, S. A reduction of the primitive symbols of the Lewis calculi. Portugaliae mathematica, Tome 8 (1949) no. 2, pp. 85-88. http://geodesic.mathdoc.fr/item/PORMA_1949__8_2_114675/