@book{67685,
	author = {Vatsya, S. Raj. and ebrary, Inc.},
	title = {Foundations and applications of variational and perturbation methods},
	publisher = {Nova Science Publishers,},
	year = {c2009.},
	address = {Hauppauge, NY :},
	url = {http://site.ebrary.com/lib/rucke/Doc?id=10660378}
}