Perhaps you should try some spelling variations:
vie » viet, vien, view
viec » vietc, vienc, viewc, viet, vien
viewc » vietwc, vienwc, viewwc, view, views
vienctnam" » vietnctnam", viennctnam", viewnctnam"
vietnam" » viettnam", vientnam", viewtnam"
viettnam" » vietttnam", vienttnam", viewttnam", vienam", vietnams"
president » resident, present

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

• Performing a fuzzy search may retrieve terms with similar spellings: "(vie or (viec or viewc)) (president or residents) of (vienctnam" or (vietnam" OR viettnam"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: "(vie or (viec or viewc)) (president or residents) of (vienctnam" OR (vietnam" OR viettnam")).
• Removing quotes may allow a broader search: (vie or (viec or viewc)) (president or residents) of (vienctnam or (vietnam OR viettnam )).
• Adding a wildcard symbol may retrieve word variants: "(vie or (viec or viewc)) (president or residents) of (vienctnam" or (vietnam" OR viettnam"))*.