@book{7590,
	author = {Norling, Ernest R.},
	title = {Perspective made easy /},
	publisher = {Dover Publications,},
	year = {1999.},
	address = {Mineola, N.Y. :},
	note = {Originally published: New York : Macmillian, 1939.},
	url = {http://www.loc.gov/catdir/description/dover033/99010310.html}
}