Perhaps you should try some spelling variations:
yan hoang » tran hoang, tan hong, anh hoang
gang gong » gongs gong, gang sung, gong gang
lang yan » wang yan, wang yang, zhang yan
hoang sy » hoang vu
hong hai » shang hai, zhong tai, dang hai
wang yue » wong yue, wang hua, wang yan
gong li » gong si, gong di, song li

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: lang yan hoang sy gang gong li ((hong hai) OR (wang yue)) ;~.
• Adding a wildcard symbol may retrieve word variants: lang yan hoang sy gang gong li ((hong hai) or (wang yue)) ;*.