Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
hien xanh » hien hanh, hien nhanh, hien khanh
tranh cua » doanh cua, manh cua
tap toan » tap doan, tap quan, bai 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 ((hien xanh) or (chieu xanh)) - canh tranh cua ((nhung cong) OR (thong cong)) tap toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien xanh) OR (chieu xanh)) - canh tranh cua ((nhung cong) OR (thong cong)) tap toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien xanh) or (chieu xanh)) - canh tranh cua ((nhung cong) OR (thong cong)) tap toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien xanh) or (chieu xanh)) - canh tranh cua ((nhung cong) OR (thong cong)) tap toan cao*.