Perhaps you should try some spelling variations:
"conferencia internacional." » "convencion internacional.", "experiencia internacional.", "cooperacion internacional."
"comercial internacional." » "comercio internacional.", "cooperacion internacional.", "convencion internacional."
"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 magistral.") or ((("conferencia internacional.") OR ("comercial internacional."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("conferencia magistral.") OR ((("conferencia internacional.") OR ("comercial internacional."))))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"conferencia magistral.\") or (((\"conferencia internacional.\") OR (\"comercial internacional.\"))))*".
• Removing quotes may allow a broader search: (( conferencia magistral. ) or ((( conferencia internacional. ) OR ( comercial internacional. ))))*.