@book{54613,
	author = {Spence, Janet T,},
	title = {Elementary statistics},
	publisher = {Appleton-Century-Crofts},
	year = {[1968]},
	series = {The Century psychology series},
	address = {New York,},
	edition = {2d ed.},
	note = {First ed. by B. J. Underwood and others.}
}