Perhaps you should try some spelling variations:
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
thanh tung » thanh cong
nhung cong » dung cong, thong cong, hang cong
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than
tung va » trung va, tuong va, dung va

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 - thanh tung va nhung cong ((dan toan) OR (dan than)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo chieu sach - thanh tung va nhung cong ((dan toan) OR (dan than)) cao".
• Adding a wildcard symbol may retrieve word variants: theo chieu sach - thanh tung va nhung cong ((dan toan) OR (dan than)) cao*.