Perhaps you should try some spelling variations:
yuan cheng » yuan chang, huang cheng, yu cheng
tuan china » wuhan china, can china, taiwan china
yuan wang » yan wang, yuan kang, yuan chang
ren yang » chen yang, dan yang, pei yang
wong yue » wang yue, hong yu
dr wong » dr ong, dr congo, dr kongo
yang » ryang
yan » ryan

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((yuan wang) or (yuan cheng)) tuan china ((ren yang) OR (ren yan)) dr wong yue ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((yuan wang) OR (yuan cheng)) tuan china ((ren yang) OR (ren yan)) dr wong yue ;*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((yuan wang) or (yuan cheng)) tuan china ((ren yang) OR (ren yan)) dr wong yue ;*".