Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » dung cong, thong cong, hang cong
tranh cua » doanh cua, manh cua
cua nhung » va nhung
bai toan » bai 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 sang) or (chieu sach)) - hanh tranh cua nhung cong ((bai toan) or (tan tran)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (chieu sach)) - hanh tranh cua nhung cong ((bai toan) OR (tan tran)) cau.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (chieu sach)) - hanh tranh cua nhung cong ((bai toan) or (tan tran)) cau*.