Perhaps you should try some spelling variations:
yuan cheng » yuan chang, huang cheng, yu cheng
than china » tuan china, han china, wuhan china
china chen » china shen, china china, china chang
chen yang » chen rong
yan wang » yuan wang, yang yang, qian wang
wong yue » wang yue, hong yu
yang dr » yang di, yang d, yang du
dr wong » dr ong, dr congo, dr kongo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((yan wang) or (yuan cheng)) than china chen yang dr wong yue ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((yan wang) OR (yuan cheng)) than china chen yang dr wong yue ;.
• Adding a wildcard symbol may retrieve word variants: ((yan wang) or (yuan cheng)) than china chen yang dr wong yue ;*.