Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
hang cong » dang cong, hang nong, bang cong
thang va » trang va, thong va, thanh va
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan cau » toan cao, toan ban, toan tap

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 sach - hanh ((thang va) or (hang va)) hang cong tac toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - hanh ((thang va) OR (hang va)) hang cong tac toan cau.
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - hanh ((thang va) or (hang va)) hang cong tac toan cau*.