Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
dung cong » dung trong
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chiet tach) or (chieu sach)) - canh ((trinh va) OR (trinh ve)) dung cong san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chiet tach) OR (chieu sach)) - canh ((trinh va) OR (trinh ve)) dung cong san toan ban*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chiet tach) or (chieu sach)) - canh ((trinh va) OR (trinh ve)) dung cong san toan ban*".