@article{2174, author = {Fitch, Frederic B.}, title = {Intuitionistic modal logic with quantifiers}, journal = {Portugaliae mathematica}, volume = {7}, year = {1948}, pages = {113-118}, zbl = {0036.00804}, mrnumber = {0029844}, language = {en}, url = {http://dml.mathdoc.fr/item/2174} }
Fitch, Frederic B. Intuitionistic modal logic with quantifiers. Portugaliae mathematica, Tome 7 (1948) pp. 113-118. http://gdmltest.u-ga.fr/item/2174/