@article{1093891106,
author = {Morgan, Charles G.},
title = {Truth, falsehood, and contingency in first-order predicate calculus.},
journal = {Notre Dame J. Formal Logic},
volume = {14},
number = {1},
year = {1973},
pages = { 536-542},
language = {en},
url = {http://dml.mathdoc.fr/item/1093891106}
}
Morgan, Charles G. Truth, falsehood, and contingency in first-order predicate calculus.. Notre Dame J. Formal Logic, Tome 14 (1973) no. 1, pp. 536-542. http://gdmltest.u-ga.fr/item/1093891106/