Perhaps you should try some spelling variations:
yuan china » tuan china, yunnan china, wuhan china
china gene » china gender, china agenda
yan yuan » yan guan, fang yuan, nan yan
yang jui » yang judy, yang xi, yang yi
wong sam » wong sau, wong lai, kong sar
wong siu » wong shiu, kong siu, wong sau
wang » wing, wan, lang

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: wang yan yuan china gene ((yang jui) OR (yang di)) ((wong sam) OR (wong siu)) ;~.
• Adding a wildcard symbol may retrieve word variants: wang yan yuan china gene ((yang jui) or (yang di)) ((wong sam) or (wong siu)) ;*.