Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
theo chieu » ho chieu, theo chu, thi chieu
trang va » tran van, hang va
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan tap » toan ban
tang va » tang van, thang va, tang vat

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((theo chieu) or (theo tieu)) xanh - hanh ((tang va) OR (trang va)) nhung cong tac toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((theo chieu) OR (theo tieu)) xanh - hanh ((tang va) OR (trang va)) nhung cong tac toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((theo chieu) or (theo tieu)) xanh - hanh ((tang va) OR (trang va)) nhung cong tac toan tap".
• Adding a wildcard symbol may retrieve word variants: ((theo chieu) or (theo tieu)) xanh - hanh ((tang va) OR (trang va)) nhung cong tac toan tap*.