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