Perhaps you should try some spelling variations:
kyoung yun » young yun, kyoung yang, hyoung gun
han zhang » han chang, hao zhang, yan zhang
zhang yan » zhang fan, zhang jian, wang yan
yan hyun » yan kun, yang yun
yan yuan » yan guan, fang yuan, nan yan
yu chen » yu cheng, yi chen, yulu chen
yan yu » yun yu, yang yue, yang yun

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

• Performing a fuzzy search may retrieve terms with similar spellings: han zhang yan yu chen ((yan hyun) or (yan yuan)) kyoung yun ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: han zhang yan yu chen ((yan hyun) OR (yan yuan)) kyoung yun ;*.