@book{71221,
	author = {Henle, Michael},
	title = {Which numbers are real? /},
	publisher = {Mathematical Association of America,},
	year = {2012},
	series = {Classroom resource materials},
	address = {Washington, D.C. :},
	url = {http://www.loc.gov/catdir/enhancements/fy1212/2012937493-t.html}
}