Perhaps you should try some spelling variations:
"serie lecturas de clases." » "serie letras de clases.", "serie lectura de clases.", "serie lecturas de clase.", "serie lecturas de bases."
"serie lacteas la clase." » "serie letras la clase.", "serie lacteos la clase.", "serie lacteos las clase.", "serie lacteas y clase."
"serie actas la clase." » "serie letras la clase.", "serie fichas la clase.", "serie actis la clase.", "serie actos la clase.", "serie actas de clase."

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 lacteas la clase.") OR ("serie actas la clase."))) or ("serie lecturas de clases."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("serie lacteas la clase.") OR ("serie actas la clase."))) OR ("serie lecturas de clases.")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"serie lacteas la clase.\") OR (\"serie actas la clase.\"))) or (\"serie lecturas de clases.\"))".
• Removing quotes may allow a broader search: (((( serie lacteas la clase. ) OR ( serie actas la clase. ))) or ( serie lecturas de clases. )).
• Adding a wildcard symbol may retrieve word variants: (((("serie lacteas la clase.") OR ("serie actas la clase."))) or ("serie lecturas de clases."))*.