@article{1250521433,
author = {Nishitani, Tatsuo},
title = {Energy inequality for non strictly hyperbolic operators in the Gevrey class},
journal = {J. Math. Kyoto Univ.},
volume = {23},
number = {4},
year = {1983},
pages = { 739-773},
language = {en},
url = {http://dml.mathdoc.fr/item/1250521433}
}
Nishitani, Tatsuo. Energy inequality for non strictly hyperbolic operators in the Gevrey class. J. Math. Kyoto Univ., Tome 23 (1983) no. 4, pp. 739-773. http://gdmltest.u-ga.fr/item/1250521433/