@book{543990,
	author = {Langley, Russell.},
	title = {Practical statistics simply explained.},
	publisher = {Dover Publications},
	year = {[1971, c1970]},
	address = {New York,},
	edition = {Rev. ed.},
	note = {1968 ed. has title: Practical statistics for non-mathematical people.},
	url = {http://www.loc.gov/catdir/description/dover032/77145771.html}
}