@inbook{a4a84e433e5d4cecab91a1e034b62836,
title = "WKB-approximations from the viewpoint of perturbation theory",
abstract = "In this work analogs of the classical WKB-approximation theorems covering nonsmooth, rapidly growing and oscillating potentials are obtained.",
author = "N. Chernyavskaya and L. Shuster",
year = "1990",
language = "American English",
series = "Operator Theory: Advances and Applications",
publisher = "Birkh{\"a}user",
pages = "119--123",
editor = "L. Shuster",
booktitle = "Order,Disorder and Chaos in Quantum Systems",
}