Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
thanh tung » thanh cong
hieu lang » chieu sang, hieu quang, nhieu tang
dang cong » dung cong
tung cua » trung cua, tuong cua, dung cua
ban toan » bai toan, ban than, van toan
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) or (chieu sach)) - thanh tung cua ((dung trong) or (dang cong)) ban toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (chieu sach)) - thanh tung cua ((dung trong) OR (dang cong)) ban toan ban.
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (chieu sach)) - thanh tung cua ((dung trong) or (dang cong)) ban toan ban*.