@book{14044,
	author = {Lazutkin, Vladimir F.},
	title = {KAM theory and semiclassical approximations to eigen functions with an addendum by A. I. Shnirelman},
	publisher = {Springer-Verlag},
	year = {1993},
	series = {Ergebnisse der Mathematik und ihrer grenzgebiete. 3 Folge, Ban 24. },
	address = {Berlin}
}