Perhaps you should try some spelling variations:
"nguyen can minh khai" » "nguyen van minh khai", "nguyen xuan minh khai", "nguyen cong minh khai", "nguyen can minh chau", "nguyen can minh chi", "nguyen can minh pham", "nguyen cao minh khai", "nguyen dan minh khai"
"nguyen ban minh khue" » "nguyen bang minh khue", "nguyen van minh khue", "nguyen tan minh khue", "nguyen ban tinh khue", "nguyen ban linh khue"
"nguyen thi minh khai" » "nguyen thi minh chau", "nguyen thi minh chi", "nguyen thi minh pham", "nguyen chi minh khai", "nguyen thi hanh khai", "nguyen thi bich khai"

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: (((("nguyen can minh khai") OR ("nguyen ban minh khue"))) OR ("nguyen thi minh khai"))~.
• Removing quotes may allow a broader search: (((( nguyen can minh khai ) or ( nguyen ban minh khue ))) or ( nguyen thi minh khai ))~.
• Adding a wildcard symbol may retrieve word variants: (((("nguyen can minh khai") or ("nguyen ban minh khue"))) or ("nguyen thi minh khai"))*.