@book{9559,
	author = {Erickson, Jon. and Vegas, Ramón.},
	title = {Las Edades del hielo },
	publisher = {McGraw-Hill, },
	year = {1991.},
	series = {Serie McGraw-Hill de divulgación científica},
	address = {Madrid [etc.] : },
	note = {Bibliogr.: p. 201-206.}
}