@article{1093893588,
author = {Williams, H. P.},
title = {A formalisation of the arithmetic of the ordinals less than $W^\omega$.},
journal = {Notre Dame J. Formal Logic},
volume = {10},
number = {1},
year = {1969},
pages = { 77-89},
language = {en},
url = {http://dml.mathdoc.fr/item/1093893588}
}
Williams, H. P. A formalisation of the arithmetic of the ordinals less than $W^\omega$.. Notre Dame J. Formal Logic, Tome 10 (1969) no. 1, pp. 77-89. http://gdmltest.u-ga.fr/item/1093893588/