@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/