Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
trong van » trong cac
hang cong » dang cong, hang nong, bang cong
tang van » dang van, hoang van, tang luan
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cao » toan ban, toan tap

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

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