Perhaps you should try some spelling variations:
wang oanh » wang yan, dang anh, wang ban
wang yang » wang yan, wang liang, wang yanling
yang john » young john, king john, yang jun
tran hua » tan hua, tuan hua
tran duc » tran dat, tran dai
yang jin » yang jie, yang jun, ying jin
wong sam » wong sau, wong lai, kong sar

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) or (wang yang)) ((tran hua) OR (tran duc)) chen ((yang john) or (yang jin)) wong sam ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang oanh) OR (wang yang)) ((tran hua) OR (tran duc)) chen ((yang john) OR (yang jin)) wong sam ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang oanh) or (wang yang)) ((tran hua) OR (tran duc)) chen ((yang john) or (yang jin)) wong sam ;".
• Adding a wildcard symbol may retrieve word variants: ((wang oanh) or (wang yang)) ((tran hua) OR (tran duc)) chen ((yang john) or (yang jin)) wong sam ;*.