Perhaps you should try some spelling variations:
chieu sach » chiet tach, chieu sang, chieu xanh
thong cong » trong cong, tong cong, thong thong
tranh cua » doanh cua, manh cua
cua thong » cua thuong, cua khong, cua tong
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
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 (chinh sach)) - canh tranh cua thong cong bai toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (chinh sach)) - canh tranh cua thong cong bai toan cao.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (chinh sach)) - canh tranh cua thong cong bai toan cao*.