Perhaps you should try some spelling variations:
"serie letras a clave." » "serie las a clave.", "serie letras la clave.", "serie letras al clave.", "serie letras y clave.", "serie letras i clave.", "serie letras una clave."
"serie poetas la clave." » "seis poetas la clave.", "serie notas la clave.", "segre poetas la clave.", "serie poeta la clave.", "serie poetas una clave.", "serie poetas de clave.", "serie poetas la clase.", "serie poetas la llave.", "serie poetas en clave.", "serie poetas li clave.", "serie poetas ly clave.", "serie poetas luna clave."
"serie actas a clave." » "serie fichas a clave.", "serie actas i clave.", "serie actas y clave.", "serie actas v clave.", "serie actas una clave."

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("serie actas a clave.") or ("serie letras a clave."))) or ("serie poetas la clave."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("serie actas a clave.") OR ("serie letras a clave."))) OR ("serie poetas la clave.")).
• Removing quotes may allow a broader search: (((( serie actas a clave. ) or ( serie letras a clave. ))) or ( serie poetas la clave. )).
• Adding a wildcard symbol may retrieve word variants: (((("serie actas a clave.") or ("serie letras a clave."))) or ("serie poetas la clave."))*.