Perhaps you should try some spelling variations:
"estudios humanisticos de." » "estudios linguisticos de.", "estudios humanisticas de.", "estudios humanistica de.", "estudios humanisticos y."
"estudio las especies." » "estudio de especies.", "estudio la especies.", "estudiar las especies.", "estudio a especies."
"estudios a especies." » "estudios e especies.", "estudios d especies.", "estudios _ especies.", "estudios y especies.", "estudios de especies.", "estudios en especies."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("estudios humanisticos de.") or ((("estudios a especies.") or ("estudio las especies."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("estudios humanisticos de.") OR ((("estudios a especies.") OR ("estudio las especies."))))*.
• Removing quotes may allow a broader search: (( estudios humanisticos de. ) or ((( estudios a especies. ) or ( estudio las especies. ))))*.