Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » thong cong, hang cong, nhung don
hieu manh » hieu nganh, dieu hanh, hien hanh
trung cua » truong cua, trung tuan, trung cap
dung cong » dung trong
san toan » van toan, dan toan, manh toan
toan cau » 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 ((hieu manh) or (chieu xanh)) - thanh trung cua ((nhung cong) OR (dung cong)) san toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu manh) OR (chieu xanh)) - thanh trung cua ((nhung cong) OR (dung cong)) san toan cau*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu manh) or (chieu xanh)) - thanh trung cua ((nhung cong) OR (dung cong)) san toan cau*".