Perhaps you should try some spelling variations:
"serie actas de clase." » "serie letras de clase.", "serie cartas de clase.", "serie actas de clacso.", "serie actas la clase."
"serie actas del bases." » "serie letras del bases.", "serie actas de bases.", "serie actas en bases.", "serie actas del babel.", "serie cartas del bases."
"serie fichas de clase." » "serie fichas de clacso.", "serie fichas la 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 actas de clase.") OR ("serie fichas de clase."))) or ("serie actas del bases."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("serie actas de clase.") OR ("serie fichas de clase."))) OR ("serie actas del bases."))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"serie actas de clase.\") OR (\"serie fichas de clase.\"))) or (\"serie actas del bases.\"))*".
• Removing quotes may allow a broader search: (((( serie actas de clase. ) OR ( serie fichas de clase. ))) or ( serie actas del bases. ))*.