@book{132129,
	author = {Rio, Gabriel J. and Purvin & Gertz and Rio, Gabriel J.},
	title = {The World of LPG at the Turn of the Millennium},
	publisher = {Purvin & Gertz},
	year = {2000},
	address = {Houston, Texas},
	note = {Sitio visitado en julio de 2001 ; Navegadores de Internet},
	url = {http://www.purvingertz.com/gbr03_2000.html}
}