@article{GDZPPN00244545X,
title = {Estimates for hyperbolic equations with non-convex characteristics.},
journal = {Mathematische Zeitschrift},
volume = {221},
year = {1996},
pages = {521-532},
zbl = {0867.35013},
url = {http://dml.mathdoc.fr/item/GDZPPN00244545X}
}
Sugimoto, Mitsuru. Estimates for hyperbolic equations with non-convex characteristics.. Mathematische Zeitschrift, Tome 221 (1996) pp. 521-532. http://gdmltest.u-ga.fr/item/GDZPPN00244545X/