Perhaps you should try some spelling variations:
"internationale conferentie opposition" » "international conference opposition" (Expand Search)
"internationale des opposition" » "internationale d'ete opposition" (Expand Search)
"international de opposition" » "international d'ete opposition" (Expand Search)

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("international de opposition") OR ((((("internationale de l'opposition") OR ("internationale conferentie opposition"))) OR ((("internationale des opposition") OR ("internationale des propositions"))))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"international de opposition\") OR (((((\"internationale de l'opposition\") OR (\"internationale conferentie opposition\"))) OR (((\"internationale des opposition\") OR (\"internationale des propositions\"))))))*".
• Removing quotes may allow a broader search: (( international de opposition ) OR ((((( internationale de l'opposition ) OR ( internationale conferentie opposition ))) OR ((( internationale des opposition ) OR ( internationale des propositions ))))))*.