@book{16385,
	author = {Lanczos, Cornelius.},
	title = {The variational principles of mechanics},
	publisher = {Dover},
	year = {1986},
	address = {New York},
	edition = {4th},
	note = {"Unabridged republication of the 4th ed. published by Univ. of Toronto Pr., Toronto, 1970".}
}