@article{01370653,
title = {Weakly hyperbolic equations with time degeneracy in Sobolev spaces.},
journal = {Abstract and Applied Analysis},
volume = {2},
year = {1997},
pages = {239-256},
doi = {10.1155/S1085337597000377},
zbl = {0938.35109},
language = {en},
url = {http://dml.mathdoc.fr/item/01370653}
}
Reissig, Michael. Weakly hyperbolic equations with time degeneracy in Sobolev spaces.. Abstract and Applied Analysis, Tome 2 (1997) pp. 239-256. doi : 10.1155/S1085337597000377. http://gdmltest.u-ga.fr/item/01370653/