Perhaps you should try some spelling variations:
"entorno virtuales oecc." » "entornos virtuales oecc.", "entorno virtual oecc.", "entornos visuales oecc.", "entorno virtuales de.", "entorno virtuales en.", "entorno virtuales tic."
"estudios visuales oecc." » "estudios sociales oecc.", "estudios visuales en.", "estudios visuales de."
"estudios visuales del." » "estudios sociales del.", "estudios visuales de.", "estudios visual del.", "estudios visuales en."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("entorno virtuales oecc.") or ((("estudios visuales oecc.") OR ("estudios visuales del."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("entorno virtuales oecc.") OR ((("estudios visuales oecc.") OR ("estudios visuales del.")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"entorno virtuales oecc.\") or (((\"estudios visuales oecc.\") OR (\"estudios visuales del.\"))))".
• Removing quotes may allow a broader search: (( entorno virtuales oecc. ) or ((( estudios visuales oecc. ) OR ( estudios visuales del. )))).
• Adding a wildcard symbol may retrieve word variants: (("entorno virtuales oecc.") or ((("estudios visuales oecc.") OR ("estudios visuales del."))))*.