@book{10428,
	author = {Kryloff,N. and Bogoli͡ubov, N. N.},
	title = {Introduction to non-linear mechanics /},
	publisher = {Kraus Reprint Co.,},
	year = {1970.},
	series = {Annals of mathematics studies ;},
	address = {New York :},
	note = {A reprint of the Princeton University Press edition of 1947.}
}