Perhaps you should try some spelling variations:
yihan guan » yan guan
yang guang » yang yang, yan guan, yang liang
yan yuan » yan guan, fang yuan, nan yan
tan yong » tan hong, tan kong, tan yang
yong duc » tung duc, long du, yong c
duc dan » duc dang, duc tran, duc phan
dan hai » dang hai, dan phan, dann hat
wang » wing, wan, lang

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 hyoung ((((yan yuan) OR (yihan guan))) OR (yang guang)) tan yong duc dan hai ;~.
• Adding a wildcard symbol may retrieve word variants: wang hyoung ((((yan yuan) or (yihan guan))) or (yang guang)) tan yong duc dan hai ;*.