@article{1077378481,
author = {Malitz, Jerome},
title = {Universal classes in infinitary languages},
journal = {Duke Math. J.},
volume = {36},
number = {1},
year = {1969},
pages = { 621-630},
language = {en},
url = {http://dml.mathdoc.fr/item/1077378481}
}
Malitz, Jerome. Universal classes in infinitary languages. Duke Math. J., Tome 36 (1969) no. 1, pp. 621-630. http://gdmltest.u-ga.fr/item/1077378481/