Perhaps you should try some spelling variations:
chiet tach » chieu sach
doi chiet » doi chieu, doi chi, doi viet
hanh manh » hanh mang, lanh manh, hoang manh
hang dong » hang nong, hanh dong, lang dong
hang cong » dang cong, hang nong, bang cong
manh cua » doanh cua, ban cua
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: doi chiet tach - hanh manh cua ((hang dong) or (hang cong)) tinh toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chiet tach - hanh manh cua ((hang dong) OR (hang cong)) tinh toan ban.
• Adding a wildcard symbol may retrieve word variants: doi chiet tach - hanh manh cua ((hang dong) or (hang cong)) tinh toan ban*.