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)
"en internationale seminar prize" » "en international seminar prize" (Expand Search), "en internationaal seminarie prize" (Expand Search), "en internationale meeting prize" (Expand Search), "de internationale seminar prize" (Expand Search), "_ international seminar prize" (Expand Search), "eerste internationale seminar prize" (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: (("het internationaal seminar prize") OR ("en internationale seminar prize"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"het internationaal seminar prize\") OR (\"en internationale seminar prize\"))*".
• Removing quotes may allow a broader search: (( het internationaal seminar prize ) OR ( en internationale seminar prize ))*.