@article{100386,
author = {Vlastimil Pt\'ak},
title = {A combinatorial theorem on systems of inequalities and its application to analysis},
journal = {Czechoslovak Mathematical Journal},
volume = {09},
year = {1959},
pages = {629-630},
zbl = {0093.05601},
mrnumber = {0110007},
language = {en},
url = {http://dml.mathdoc.fr/item/100386}
}
Pták, Vlastimil. A combinatorial theorem on systems of inequalities and its application to analysis. Czechoslovak Mathematical Journal, Tome 09 (1959) pp. 629-630. http://gdmltest.u-ga.fr/item/100386/