Perhaps you should try some spelling variations:
chieu sang » chieu sach, hieu lang, nhieu tang
chieu xanh » chieu sach, chieu tinh, hieu manh
tranh cua » manh cua
doanh cua » doanh luan
dang cong » dung 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.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) OR (chieu xanh)) - canh ((tranh cua) or (doanh cua)) dang cong ban toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (chieu xanh)) - canh ((tranh cua) OR (doanh cua)) dang cong ban toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (chieu xanh)) - canh ((tranh cua) or (doanh cua)) dang cong ban toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (chieu xanh)) - canh ((tranh cua) or (doanh cua)) dang cong ban toan cao*.