Perhaps you should try some spelling variations:
"autores universitarios 2017." » "manuales universitarios 2017.", "jovenes universitarios 2017.", "profesores universitarios 2017.", "autores universitarios y."
"autores universitarios de." » "manuales universitarios de.", "jovenes universitarios de.", "profesores universitarios de.", "autores universitarias de.", "autores universitaria de."
"textos universitarios en." » "textos universitaria en."

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: (((("autores universitarios 2017.") or ("autores universitarios de."))) or ("textos universitarios en."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("autores universitarios 2017.") OR ("autores universitarios de."))) OR ("textos universitarios en.")).
• Removing quotes may allow a broader search: (((( autores universitarios 2017. ) or ( autores universitarios de. ))) or ( textos universitarios en. )).
• Adding a wildcard symbol may retrieve word variants: (((("autores universitarios 2017.") or ("autores universitarios de."))) or ("textos universitarios en."))*.