Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
ho chieu » theo chieu, hoc thieu, doi chieu
tranh va » tranh van, trang va, trinh va
van toan » van tuan, van tan, van thanh

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ho chieu sach - hanh tranh va ((nhung cong) OR (thong cong)) ((xuan toan) OR (van toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho chieu sach - hanh tranh va ((nhung cong) OR (thong cong)) ((xuan toan) or (van toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: ho chieu sach - hanh tranh va ((nhung cong) OR (thong cong)) ((xuan toan) or (van toan)) cau*.