Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
tang vatn » tang van, dang van, tan van
tang vat » tang van, dang vat, bang vat
cong tan » cong tac, cong san, cong thanh
tran cau » tran chau, toan cau, ran cau

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 ((tang vat) or (tang vatn)) nhung cong tan tran cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - hanh ((tang vat) OR (tang vatn)) nhung cong tan tran cau*.