Perhaps you should try some spelling variations:
wang oanh » wang yan, wang yang, dang anh
chen rong » chen yang
rong john » wrong john, kong john, wong john
john wong » john song, john bonn
tran hua » tan hua, tran duc
tuan hua » tan hua, tuan vu, yuan hui
wong sam » wong sau, wong lai, kong sar

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang oanh ((tran hua) or (tuan hua)) chen rong john wong sam ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang oanh ((tran hua) OR (tuan hua)) chen rong john wong sam ;.
• Adding a wildcard symbol may retrieve word variants: wang oanh ((tran hua) or (tuan hua)) chen rong john wong sam ;*.