Perhaps you should try some spelling variations:
"serie detras de base." » "serie letras de base.", "serie lecturas de base.", "serie retratos de base.", "serie detras de bases."
"serie actas de ser." » "serie letras de ser.", "serie fichas de ser.", "serie actas del ser.", "serie cartas de ser."
"serie las alas clase." » "serie las la clase.", "serie las las clases.", "serie las hla clase.", "serie las aulas clase.", "serie las salas clase.", "serie las almas clase."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("serie las alas clase.") or ("serie actas de ser."))) or ("serie detras de base."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("serie las alas clase.") OR ("serie actas de ser."))) OR ("serie detras de base."))*.
• Removing quotes may allow a broader search: (((( serie las alas clase. ) or ( serie actas de ser. ))) or ( serie detras de base. ))*.