@article{1183738447,
author = {Cutland, Nigel},
title = {$\sum\_1$-Compactness and Ultraproducts},
journal = {J. Symbolic Logic},
volume = {37},
number = {1},
year = {1972},
pages = { 668-672},
language = {en},
url = {http://dml.mathdoc.fr/item/1183738447}
}
Cutland, Nigel. $\sum_1$-Compactness and Ultraproducts. J. Symbolic Logic, Tome 37 (1972) no. 1, pp. 668-672. http://gdmltest.u-ga.fr/item/1183738447/