@article{1093891791,
author = {Girle, Roderic A.},
title = {$S\_1\not=S0.9$.},
journal = {Notre Dame J. Formal Logic},
volume = {16},
number = {1},
year = {1975},
pages = { 339-344},
language = {en},
url = {http://dml.mathdoc.fr/item/1093891791}
}
Girle, Roderic A. $S_1\not=S0.9$.. Notre Dame J. Formal Logic, Tome 16 (1975) no. 1, pp. 339-344. http://gdmltest.u-ga.fr/item/1093891791/