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)
"de international de prize" » "de internationale de prize" (Expand Search), "_ international de prize" (Expand Search), "en internationale de prize" (Expand Search), "de internationale des prize" (Expand Search), "de international de prijzen" (Expand Search), "de international de prince" (Expand Search), "de international de prijs" (Expand Search)

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"de international de prize\") OR (\"het internationaal seminar prize\"))~".
• Removing quotes may allow a broader search: (( de international de prize ) OR ( het internationaal seminar prize ))~.
• Adding a wildcard symbol may retrieve word variants: (("de international de prize") OR ("het internationaal seminar prize"))*.