Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
chieu tinh » trieu tinh, lieu tinh, chau tinh
nhung cong » thong cong, hang cong, nhung don
hanh tang » hanh trang, anh tang, hanh mang
tang luan » dung luan
dung cong » dung trong
toan tap » toan ban
va toan » van toan, bai toan, tap toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chieu sach) or (chieu tinh)) - hanh tang luan ((nhung cong) OR (dung cong)) va toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chieu tinh)) - hanh tang luan ((nhung cong) OR (dung cong)) va toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) or (chieu tinh)) - hanh tang luan ((nhung cong) OR (dung cong)) va toan tap".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (chieu tinh)) - hanh tang luan ((nhung cong) OR (dung cong)) va toan tap*.