@book{10958,
	author = {Nayfeh, Ali Hasan,},
	title = {Perturbation methods /},
	publisher = {Wiley,},
	year = {c1973.},
	series = {Pure and applied mathematics},
	address = {New York :},
	note = {"A Wiley-Interscience publication."},
	url = {http://www.loc.gov/catdir/toc/onix02/72008068.html}
}