@article{1183731783,
author = {Fitch, Frederic B.},
title = {A Definition of Negation in Extended Basic Logic},
journal = {J. Symbolic Logic},
volume = {19},
number = {1},
year = {1954},
pages = { 29-36},
language = {en},
url = {http://dml.mathdoc.fr/item/1183731783}
}
Fitch, Frederic B. A Definition of Negation in Extended Basic Logic. J. Symbolic Logic, Tome 19 (1954) no. 1, pp. 29-36. http://gdmltest.u-ga.fr/item/1183731783/