Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
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 xanh - canh trinh ((va hang) or (va nang)) ((cong tan) OR (cong san)) phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - canh trinh ((va hang) OR (va nang)) ((cong tan) OR (cong san)) phan tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - canh trinh ((va hang) or (va nang)) ((cong tan) OR (cong san)) phan tu".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh trinh ((va hang) or (va nang)) ((cong tan) OR (cong san)) phan tu*.