@article{02099319,
title = {Positivity zones and norms of },
journal = {Publications de l'Institut Math\'ematique. Nouvelle S\'erie},
volume = {71(85)},
year = {2002},
pages = {3-7},
doi = {10.2298/PIM0271003B},
zbl = {1052.42011},
language = {en},
url = {http://dml.mathdoc.fr/item/02099319}
}
Baishanski, Bogdan M. Positivity zones and norms of . Publications de l'Institut Mathématique. Nouvelle Série, Tome 71(85) (2002) pp. 3-7. doi : 10.2298/PIM0271003B. http://gdmltest.u-ga.fr/item/02099319/