@article{1093957658,
author = {Belnap, N. D. and Leblanc, H. and Thomason, R. H.},
title = {On not strengthening intuitionistic logic.},
journal = {Notre Dame J. Formal Logic},
volume = {4},
number = {1},
year = {1963},
pages = { 313-320},
language = {en},
url = {http://dml.mathdoc.fr/item/1093957658}
}
Belnap, N. D.; Leblanc, H.; Thomason, R. H. On not strengthening intuitionistic logic.. Notre Dame J. Formal Logic, Tome 4 (1963) no. 1, pp. 313-320. http://gdmltest.u-ga.fr/item/1093957658/