@book{9563,
	author = {Erickson, Jon. and Sánchez, Alicia.},
	title = {Objetivo la tierra },
	publisher = {McGraw-Hill, },
	year = {D.L. 1992.},
	series = {Serie McGraw-Hill de divulgación científica},
	address = {Madrid [etc.] : },
	note = {Bibliogr.: p. 197-202.}
}