Perhaps you should try some spelling variations:
chiet tach » chieu sach
doi chiet » doi chieu, doi chi, doi viet
hanh tich » hanh thich, thanh tich, hanh tinh
va thong » va thuong, va phuong, he thong
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
ban cau » bang cau, ban can, van cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chiet tach - hanh tich va thong ((cong tan) or (cong san)) ban cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiet tach - hanh tich va thong ((cong tan) OR (cong san)) ban cau.
• Adding a wildcard symbol may retrieve word variants: doi chiet tach - hanh tich va thong ((cong tan) or (cong san)) ban cau*.