Perhaps you should try some spelling variations:
yuan chang » yuan cheng, huang chang, han chang
wang yuhan » wang luhang, wang yan, wang yidan
yang weng » huang weng, yang yang, yang jing
weng wang » wen wang, weng fang, hong wang
yuan kang » yuan wang, chan kang, yuan kai
dan yan » dan yang, nan yan, wang yan

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: yang weng wang yuhan dan yan ((yuan kang) OR (yuan chang)) hay ;~.
• Adding a wildcard symbol may retrieve word variants: yang weng wang yuhan dan yan ((yuan kang) or (yuan chang)) hay ;*.