@book{67440,
	author = {Callan, Scott. and Thomas, Janet M.},
	title = {Environmental economics and management :},
	publisher = {Dryden Press,},
	year = {2000.},
	address = {Fort Worth :},
	edition = {2nd ed.},
	url = {http://www.loc.gov/catdir/enhancements/fy1514/99074295-b.html}
}