@article{bwmeta1.element.bwnjournal-article-fmv114i1p10bwm,
author = {Andrzej Pelc},
title = {Solution of a problem of Ulam on countable sequences of sets},
journal = {Fundamenta Mathematicae},
volume = {112},
year = {1981},
pages = {113-118},
zbl = {0488.28002},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-fmv114i1p10bwm}
}
Pelc, Andrzej. Solution of a problem of Ulam on countable sequences of sets. Fundamenta Mathematicae, Tome 112 (1981) pp. 113-118. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-fmv114i1p10bwm/