Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
hanh hang » thanh hang, hang hang, hanh han
dung cong » dung trong
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban
va dung » van dung, va duong, vat dung
tinh » trinh, dinh, minh

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((trieu tinh) or (((chieu sach) or (chiet tach)))) - hanh hang va dung cong bai toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((trieu tinh) OR (((chieu sach) OR (chiet tach)))) - hanh hang va dung cong bai toan ban.
• Adding a wildcard symbol may retrieve word variants: ho ((trieu tinh) or (((chieu sach) or (chiet tach)))) - hanh hang va dung cong bai toan ban*.