Perhaps you should try some spelling variations:
wang oanh » wang yan, wang yang, dang anh
john song » john wong, john bonn, john ngosong
tran hua » tan hua, tuan hua
tran duc » tran dat, tran dai
ren yang » ren yan, chen yang, dan yang
tan yang » dan yang, tan ying, tan yong
song sam » wong sam, kong sar, song pae

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

• Performing a fuzzy search may retrieve terms with similar spellings: wang oanh ((tran hua) or (tran duc)) ((ren yang) or (tan yang)) john song sam ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: wang oanh ((tran hua) OR (tran duc)) ((ren yang) OR (tan yang)) john song sam ;.
• Adding a wildcard symbol may retrieve word variants: wang oanh ((tran hua) or (tran duc)) ((ren yang) or (tan yang)) john song sam ;*.