@book{56066,
	author = {Grad, Frank P.},
	title = {Treatise on environmental law},
	publisher = {M. Bender},
	year = {1973-<1981 >},
	address = {New York},
	note = {Versión impresa disponible hasta 2013.},
	url = {http://www.lexisnexis.com/lawschool/Login.aspx}
}