Perhaps you should try some spelling variations:
"het internationaal seminar prize" » "het international seminar prize" (Expand Search), "het internationaal seminarie prize" (Expand Search), "het internationaal verdrag prize" (Expand Search), "_ international seminar prize" (Expand Search), "de internationale seminar prize" (Expand Search)
"eerste internationale des prince" » "de internationale des prince" (Expand Search), "eerste internationale de prince" (Expand Search), "eerste internationale le prince" (Expand Search), "eerste internationale des principes" (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: (("eerste internationale des prince") OR ("het internationaal seminar prize"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"eerste internationale des prince\") OR (\"het internationaal seminar prize\"))*".
• Removing quotes may allow a broader search: (( eerste internationale des prince ) OR ( het internationaal seminar prize ))*.