Coleccion El Nuevo Tesoro De La Juventud -

I believe you are referring to the (The New Treasure of Youth Collection), a famous illustrated encyclopedia for young people published originally by W. M. Jackson, Inc. (and later by other publishers like Codex and Grolier).

💎 Una joya para cualquier biblioteca: Colección Completa "El Nuevo Tesoro de la Juventud" coleccion el nuevo tesoro de la juventud