@book{160982,
	author = {Estados Unidos. Department of labor and Estados Unidos. Department of labor},
	title = {Oil and Gas Well Drilling and Servicing e Tool},
	publisher = {Estados Unidos. Department of Labor},
	year = {2004},
	address = {Washington},
	note = {Sitio visitado por última vez en junio de 2004},
	url = {http://www.osha.gov/SLTC/etools/oilandgas/index.html}
}