Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, thien anh, thien danh
thanh tung » thanh cong
thuong con » thuong dong, truong cong, thuong chi
thong cong » trong cong, tong cong, thong thong
hieu manh » chieu xanh, hieu nganh, dieu hanh
tung cap » trung cap, cung cap, thong cap
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 ((thieu xanh) or (hieu manh)) - thanh tung cap ((thuong con) OR (thong cong)) ban toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (hieu manh)) - thanh tung cap ((thuong con) OR (thong cong)) ban toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) or (hieu manh)) - thanh tung cap ((thuong con) OR (thong cong)) ban toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (hieu manh)) - thanh tung cap ((thuong con) OR (thong cong)) ban toan cao*.