Perhaps you should try some spelling variations:
thanh tung » thanh cong
doi chieu » doc hieu, doi chi, ho chieu
hoc thieu » toc thieu, hoc hien
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
toan cao » toan ban, toan tap
tung va » trung va, tuong va, dung va
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doi chieu) or (hoc thieu)) xanh - thanh tung va dung ((cong tan) OR (cong san)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (hoc thieu)) xanh - thanh tung va dung ((cong tan) OR (cong san)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) or (hoc thieu)) xanh - thanh tung va dung ((cong tan) OR (cong san)) toan cao".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) or (hoc thieu)) xanh - thanh tung va dung ((cong tan) OR (cong san)) toan cao*.