@article{02214046,
title = {Time deformations of powers of the wave operator.},
journal = {Zapiski Nauchnykh Seminarov POMI},
volume = {321},
year = {2005},
pages = {213-228},
zbl = {1100.35002},
language = {en},
url = {http://dml.mathdoc.fr/item/02214046}
}
Khèkalo, S.P. Time deformations of powers of the wave operator.. Zapiski Nauchnykh Seminarov POMI, Tome 321 (2005) pp. 213-228. http://gdmltest.u-ga.fr/item/02214046/