@book{15179,
	author = {Pies, W. and Weiss, A.},
	title = {Key Element: O / Schlüsselelement: O.},
	publisher = {Springer},
	year = {Dec. 1974},
	series = {Landolt-Börnstein: Numerical Data and Functional Relationships in Science and Technology Ser.},
	address = {New York : }
}