@article{01069382,
title = {Complex powers of the wave operator.},
journal = {Portugaliae Mathematica. Nova S\'erie},
volume = {54},
year = {1997},
pages = {345-362},
zbl = {0891.35166},
language = {en},
url = {http://dml.mathdoc.fr/item/01069382}
}
Joshi, M.S. Complex powers of the wave operator.. Portugaliae Mathematica. Nova Série, Tome 54 (1997) pp. 345-362. http://gdmltest.u-ga.fr/item/01069382/