@book{130439,
	author = {EE.UU. Energy Information Administration},
	publisher = {EIA},
	year = {2001},
	series = {International Natural Gas Price Information},
	address = {Washington},
	note = {Publicación electrónica actualizada anualmente ; Disponible en HTML},
	url = {http://www.eia.doe.gov/emeu/international/gas.html#CountryPrices}
}