Perhaps you should try some spelling variations:
"conferencia internacionales." » "conferencia internacional.", "referencia internacionales.", "competencia internacional."
"conferencia ministerio." » "conferencia ministerial.", "conferencia magistral.", "conferencia monetaria."
"conferencia nacional." » "conciencia nacional.", "conferencia internacional.", "confederacion 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 internacionales.") or ("conferencia nacional."))) or ("conferencia ministerio."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("conferencia internacionales.") OR ("conferencia nacional."))) OR ("conferencia ministerio."))*.
• Removing quotes may allow a broader search: (((( conferencia internacionales. ) or ( conferencia nacional. ))) or ( conferencia ministerio. ))*.