Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
khoan cam » khoa cam, khoan va, phan cam
anh tang » anh bang, anh dang, anh nang
va thong » va thuong, va phuong, he thong
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
than cap » khan cap, thanh lap, thanh cac
tang va » trang va, tang van, thang va

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 sach - anh tang va thong ((cong tan) or (cong tac)) ((than cap) or (khoan cam))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - anh tang va thong ((cong tan) OR (cong tac)) ((than cap) OR (khoan cam)).
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - anh tang va thong ((cong tan) or (cong tac)) ((than cap) or (khoan cam))*.