Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
hanh tranh » canh tranh, hanh trinh, hanh trang
dang cong » dung cong
hang cong » hang nong, bang cong, thanh cong
tranh va » tranh van, trang va, trinh va
san toan » van toan, dan toan, 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: theo ((chieu sach) OR (chiet tach)) - hanh tranh va ((dang cong) or (hang cong)) san toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chiet tach)) - hanh tranh va ((dang cong) OR (hang cong)) san toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) OR (chiet tach)) - hanh tranh va ((dang cong) or (hang cong)) san toan cao".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) OR (chiet tach)) - hanh tranh va ((dang cong) or (hang cong)) san toan cao*.