Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
hanh trung » thanh trung, hanh trang, manh trung
nhung cong » dung cong, thong cong, hang cong
trung dap » trung cap, trung dai, trung dam
dap nhung » vap nhung, va nhung, dap ung
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.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sach) OR (chiet tach)) - hanh trung dap nhung cong ((dan toan) or (dan than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (chiet tach)) - hanh trung dap nhung cong ((dan toan) OR (dan than)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) OR (chiet tach)) - hanh trung dap nhung cong ((dan toan) or (dan than)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) OR (chiet tach)) - hanh trung dap nhung cong ((dan toan) or (dan than)) cau*.