@article{PORMA_1997__54_3_47898,
     author = {Joshi, M.S.},
     title = {Complex powers of the wave operator.},
     journal = {Portugaliae mathematica},
     pages = {345--362},
     publisher = {mathdoc},
     volume = {54},
     number = {3},
     year = {1997},
     zbl = {0891.35166},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1997__54_3_47898/}
}