Perhaps you should try some spelling variations:
sang minh » kang minah, anh minh, song min
hong than » hong tan, long thanh, hong hai
chai dan » chai onn, chai tam, shi dan
dan sang » dan yang, dan dana, dan qing
wan yan » wang yan, nan yan, wai yan
ka chai » ka chuan, kim chai
yan ka » yang ka, yuan kai

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: wan yan ka chai dan sang minh ((dang hai) OR (hong than)) ;~.
• Adding a wildcard symbol may retrieve word variants: wan yan ka chai dan sang minh ((dang hai) or (hong than)) ;*.