@article{1093883058,
author = {Tosi, P.},
title = {Normal derivability and first-order arithmetic.},
journal = {Notre Dame J. Formal Logic},
volume = {21},
number = {1},
year = {1980},
pages = { 449-466},
language = {en},
url = {http://dml.mathdoc.fr/item/1093883058}
}
Tosi, P. Normal derivability and first-order arithmetic.. Notre Dame J. Formal Logic, Tome 21 (1980) no. 1, pp. 449-466. http://gdmltest.u-ga.fr/item/1093883058/