Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
hanh tranh » canh tranh, hanh trinh, hanh trang
thong cong » trong cong, tong cong, thong thong
doc hieu » toc thieu, hoc thieu, hoc hien
tranh va » tranh van, trang va, trinh va
va thong » va thuong, va phuong, he thong
cong dan » cong san, cong tan, huong dan

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 thong cong dan ((toan ban) OR (van ban))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (theo chieu)) xanh - hanh tranh va thong cong dan ((toan ban) OR (van ban)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (theo chieu)) xanh - hanh tranh va thong cong dan ((toan ban) OR (van ban))".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (theo chieu)) xanh - hanh tranh va thong cong dan ((toan ban) OR (van ban))*.