Perhaps you should try some spelling variations:
vie » viet, view
vien » vietn, viewn, viet, bien
viec » vietc, viewc, viet
vietnamese » viettnamese, viewtnamese
vientnam » vietntnam, viewntnam, viettnam, bientnam, vietnam, vietnams
vienam » vietnam, viewnam, vietam, bienam, vietnams
president » resident, present

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((vie OR vien) OR viec) (president OR residents) of (vietnamese OR (vientnam OR vienam) )~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vie or vien) or viec) (president or residents) of (vietnamese or (vientnam OR vienam) )~".
• Adding a wildcard symbol may retrieve word variants: ((vie or vien) or viec) (president or residents) of (vietnamese or (vientnam OR vienam) )*.