Perhaps you should try some spelling variations:
"vietnamese americanns" » "vietnamese american", "vietnam's american", "vietnam american", "vietnamese americannns", "vietnam's americannns", "vietnam americannns"
"vietnamese americans" » "vietnamese americanns", "vietnam's americanns", "vietnam americanns", "vietnamese american"
"vietnamese america" » "vietnamese american", "vietnam's american", "vietnam american"

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: (((("vietnamese americans") OR ("vietnamese americanns"))) OR ("vietnamese america")).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"vietnamese americans\") OR (\"vietnamese americanns\"))) or (\"vietnamese america\"))".
• Removing quotes may allow a broader search: (((( vietnamese americans ) OR ( vietnamese americanns ))) or ( vietnamese america )).
• Adding a wildcard symbol may retrieve word variants: (((("vietnamese americans") OR ("vietnamese americanns"))) or ("vietnamese america"))*.