Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
dung cong » dung trong
cong tac » cong ty
tac toan » tap toan, tam toan, hach toan
toan ban » van ban
tra van » tran van, trang van, tranh van
ta van » tan van, tap van, va van

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 - thanh ((tra van) or (ta van)) dung cong tac toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - thanh ((tra van) OR (ta van)) dung cong tac toan ban.
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - thanh ((tra van) or (ta van)) dung cong tac toan ban*.