@article{01669217,
title = {The upper bound conjecture for arrangements of halfspaces.},
journal = {Beitr\"age zur Algebra und Geometrie},
volume = {42},
year = {2001},
pages = {431-437},
zbl = {1001.52012},
language = {en},
url = {http://dml.mathdoc.fr/item/01669217}
}
Wesp, Gerhard. The upper bound conjecture for arrangements of halfspaces.. Beiträge zur Algebra und Geometrie, Tome 42 (2001) pp. 431-437. http://gdmltest.u-ga.fr/item/01669217/