Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
hanh trung » thanh trung, hanh trang, manh trung
tuan hung » tran hung, luan hung, tuan dung
hung cong » nhung cong, hung cuong, phung cong
cong ban » cong bang, cong san, cong tan
ban toan » bai toan, ban than, van toan
toan cao » toan ban, toan tap

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: hoc ((chieu xanh) OR (chieu sang)) - ((hanh trung) OR (canh tranh)) tuan hung cong ban toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu xanh) OR (chieu sang)) - ((hanh trung) or (canh tranh)) tuan hung cong ban toan cao~".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) OR (chieu sang)) - ((hanh trung) or (canh tranh)) tuan hung cong ban toan cao*.