Perhaps you should try some spelling variations:
tien thanh » tien thinh, tran thanh, den thanh
canh trinh » hanh trinh, canh tinh, anh trinh
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
hoc tien » hoc tieng, hoc hien, hoc vien
dan toan » van toan, dan than, 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 tien thanh - ((canh trinh) or (canh tranh)) va ((nhung cong) OR (thong cong)) dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc tien thanh - ((canh trinh) OR (canh tranh)) va ((nhung cong) OR (thong cong)) dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc tien thanh - ((canh trinh) or (canh tranh)) va ((nhung cong) OR (thong cong)) dan toan cau".
• Adding a wildcard symbol may retrieve word variants: hoc tien thanh - ((canh trinh) or (canh tranh)) va ((nhung cong) OR (thong cong)) dan toan cau*.