@article{bwmeta1.element.bwnjournal-article-fmv31i1p21bwm,
author = {Edward Szpilrajn},
title = {The characteristic function of a sequence of sets and some of its applications},
journal = {Fundamenta Mathematicae},
volume = {30},
year = {1938},
pages = {47-66},
zbl = {0019.29701},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-fmv31i1p21bwm}
}
Szpilrajn, Edward. The characteristic function of a sequence of sets and some of its applications. Fundamenta Mathematicae, Tome 30 (1938) pp. 47-66. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-fmv31i1p21bwm/