Perhaps you should try some spelling variations:
vie » viet, view
vien » vietn, viewn, viet, bien
viec » vietc, viewc, viet
viewctnam" » vietwctnam", viewwctnam", vietnam"
vientnam" » vietntnam", viewntnam", viettnam", bientnam", vietnam", vienam", vietnams"
vietntnam" » viettntnam", viewtntnam", vietnam"
resident » president, resilient, residence
residents » presidents, resilients, residences

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) (resident or residents) of (viewctnam" OR (vientnam" or vietntnam"))~.
• Removing quotes may allow a broader search: ((vie or vien) or viec) (resident or residents) of (viewctnam or (vientnam or vietntnam ))~.
• Adding a wildcard symbol may retrieve word variants: "((vie or vien) or viec) (resident or residents) of (viewctnam" or (vientnam" or vietntnam"))*.