@article{1183386722,
author = {McKinsey, J. C. C.},
title = {Proof of the Independence of the Primitive Symbols of Heyting's Calculus of Propositions},
journal = {J. Symbolic Logic},
volume = {4},
number = {1},
year = {1939},
pages = { 155-158},
language = {en},
url = {http://dml.mathdoc.fr/item/1183386722}
}
McKinsey, J. C. C. Proof of the Independence of the Primitive Symbols of Heyting's Calculus of Propositions. J. Symbolic Logic, Tome 4 (1939) no. 1, pp. 155-158. http://gdmltest.u-ga.fr/item/1183386722/