Perhaps you should try some spelling variations:
thanh trung » thanh tung
chi sach » chinh sach, chieu sach, moi sach
tac dung » sach dung, tin dung, van dung
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap
co sach » bo sach, cuon sach, hoc sach

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((chi sach) or (co sach)) - thanh trung ((tac dung) OR (xay dung)) cong dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chi sach) OR (co sach)) - thanh trung ((tac dung) OR (xay dung)) cong dan toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chi sach) or (co sach)) - thanh trung ((tac dung) OR (xay dung)) cong dan toan cao".
• Adding a wildcard symbol may retrieve word variants: doi ((chi sach) or (co sach)) - thanh trung ((tac dung) OR (xay dung)) cong dan toan cao*.