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