By Gamow, George.
Buenos Aires : Eudeba, 1976 .
139 p. : 18 cm.

By Gamow, George.
Buenos Aires : Eudeba, 1968

By Guillemin, Amadeo.
Barcelona : Montaner y Simon, 1882 .
397 p. : 30 cm.

By Burbano de Ercilla, S..
México : Alfaomega, 2006 , Reposición Ing.Montenegro reemp.Inv.8781. 970-15-1106-9

By Swick, Clarence H..
Washington : U.S.Dep.of Commerce, 1942 .
82 p. : 26 cm.