Perhaps you should try some spelling variations:
thanh trung » thanh tung
doc hieu » hoc thieu, hoc hien
cong ban » cong bang, cong san, cong tan
ban danh » ban doanh, ban hanh, ban dan
danh dau » lanh dao, hang dau, danh tu
va hang » van hang, va lang, va hanh
va nang » van nang, da nang, cam nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc hieu) or (toc thieu)) xanh - thanh trung ((va hang) OR (va nang)) cong ban danh dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (toc thieu)) xanh - thanh trung ((va hang) OR (va nang)) cong ban danh dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (toc thieu)) xanh - thanh trung ((va hang) OR (va nang)) cong ban danh dau".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (toc thieu)) xanh - thanh trung ((va hang) OR (va nang)) cong ban danh dau*.