@book{149537,
	author = {Eskeland, Gunnar S.},
	title = {Environmental protection and optimal taxation},
	publisher = {World Bank Group},
	year = {2001},
	address = {Washington},
	note = {Página visitada en junio de 2003. ; Navegadores de Internet},
	url = {http://econ.worldbank.org/files/1322_wps2510.pdf}
}