Perhaps you should try some spelling variations:
"nguyen chi minh khai" » "nguyen can minh khai", "nguyen nhu minh khai", "nguyen hai minh khai", "nguyen chi minh khue", "nguyen chi minh chi", "nguyen chi minh pham"
"nguyen chi minh chau" » "nguyen can minh chau", "nguyen nhu minh chau", "nguyen hai minh chau", "nguyen chi tinh chat"
"nguyen thi minh khai" » "nguyen thi minh khue", "nguyen thi minh chi", "nguyen thi minh pham", "nguyen thi hanh khai", "nguyen thi bich khai"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (((("nguyen chi minh khai") OR ("nguyen chi minh chau"))) or ("nguyen thi minh khai"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("nguyen chi minh khai") OR ("nguyen chi minh chau"))) OR ("nguyen thi minh khai"))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"nguyen chi minh khai\") OR (\"nguyen chi minh chau\"))) or (\"nguyen thi minh khai\"))*".
• Removing quotes may allow a broader search: (((( nguyen chi minh khai ) OR ( nguyen chi minh chau ))) or ( nguyen thi minh khai ))*.