Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
hanh tranh » canh tranh, hanh trinh, hanh trang
hang cong » dang cong, hang nong, bang cong
doc hieu » toc thieu, hoc thieu, hoc hien
tranh va » tranh van, trang va, trinh va
cong dan » cong san, cong tan, huong dan
va hang » van hang, va nang, va lang
dan van » dang van, doan van, dao van

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 (theo chieu)) xanh - hanh tranh va hang cong dan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (theo chieu)) xanh - hanh tranh va hang cong dan van ban.
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (theo chieu)) xanh - hanh tranh va hang cong dan van ban*.