Perhaps you should try some spelling variations:
yuhan chang » yuan chang, han chang, yuhuan huang
wang yuhan » wang luhang, wang yan, wang yidan
chang run » chang yun, chang hsun, chang ann
john song » john wong, john bonn, john ngosong
tan yang » dan yang, tan ying, tao yang
tan yong » tan hong, tan kong, tan ying
kim song » kim young, kim eung

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 yuhan chang run ((tan yang) OR (tan yong)) ((john song) OR (kim song)) sar ;~.
• Adding a wildcard symbol may retrieve word variants: wang yuhan chang run ((tan yang) or (tan yong)) ((john song) or (kim song)) sar ;*.