@article{1183733110,
author = {Fitch, Frederic B.},
title = {An Extensional Variety of Extended Basic Logic},
journal = {J. Symbolic Logic},
volume = {23},
number = {1},
year = {1958},
pages = { 13-21},
language = {en},
url = {http://dml.mathdoc.fr/item/1183733110}
}
Fitch, Frederic B. An Extensional Variety of Extended Basic Logic. J. Symbolic Logic, Tome 23 (1958) no. 1, pp. 13-21. http://gdmltest.u-ga.fr/item/1183733110/