Perhaps you should try some spelling variations:
chiet tach » chieu sach
hieu lang » chieu sang, hieu quang, nhieu tang
hanh hanh » hanh han, xanh hanh, nhanh thanh
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan ban » van ban
vi dung » vi ung, vi dong, viet dung
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) or (chiet tach)) - hanh hanh ((vi dung) OR (va dung)) cong san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (chiet tach)) - hanh hanh ((vi dung) OR (va dung)) cong san toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) or (chiet tach)) - hanh hanh ((vi dung) OR (va dung)) cong san toan ban".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (chiet tach)) - hanh hanh ((vi dung) OR (va dung)) cong san toan ban*.