Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
cong thanh » dong thanh, cong trinh, cong tan
thanh toan » thanh hoa, thanh san
toan thuc » toan hoc, dan thuc, nhan thuc
thuc hung » thuc chung, thuc nhung, thuc dung
hung cong » nhung cong, hung cuong, phung cong
toan cac » toan cao, toan cau, toan xac

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)) - tinh toan thuc hung cong thanh toan cac~.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu xanh) or (chieu sang)) - tinh toan thuc hung cong thanh toan cac*.