@book{3816,
	author = {Callan, Scott. and Thomas, Janet M.},
	title = {Environmental economics & management :},
	publisher = {Southern-Western Cengage learning,},
	year = {c2013.},
	address = {United States :},
	edition = {6th ed.},
	note = {Includes index.},
	url = {http://catdir.loc.gov/catdir/enhancements/fy1307/2012935809-t.html}
}