Perhaps you should try some spelling variations:
"conferencia internacional." » "convencion internacional.", "comercial internacional.", "experiencia internacional."
"conferencia magistrales." » "conferencias magistrales.", "conferencias magistraleses.", "conferencia ministeriales.", "conferencia nacionales."
"conferencia magistral." » "conferencias magistrales.", "conferencia ministerial.", "conferencia nacional."

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("conferencia magistrales.") or ("conferencia internacional."))) or ("conferencia magistral."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("conferencia magistrales.") OR ("conferencia internacional."))) OR ("conferencia magistral."))*.
• Removing quotes may allow a broader search: (((( conferencia magistrales. ) or ( conferencia internacional. ))) or ( conferencia magistral. ))*.