@book{151186,
	author = {Petróleos Mexicanos, Pemex},
	title = {Anuario estadístico 2002},
	publisher = {México},
	year = {2002},
	address = {PEMEX},
	note = {Navegadores de Internet ; Adobe Acrobat (PDF)},
	url = {http://www.pemex.com/index.cfm/action/content/sectionID/1/catID/237/subcatID/246/index.cfm?action=content&sectionID=1&catID=237&subcatID=246}
}