Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hang cong » dang cong, hang nong, bang cong
ho chieu » theo chieu, hoc thieu, doi chieu
trinh va » trinh van, trinh vat, trinh vi
trinh ve » trinh he, trinh vi, trinh viet
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu sach - hanh ((trinh va) OR (trinh ve)) hang cong ((dan toan) OR (dan than)) ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu sach - hanh ((trinh va) or (trinh ve)) hang cong ((dan toan) OR (dan than)) ban~".
• Adding a wildcard symbol may retrieve word variants: ho chieu sach - hanh ((trinh va) or (trinh ve)) hang cong ((dan toan) OR (dan than)) ban*.