Perhaps you should try some spelling variations:
thanh trung » thanh tung
hien thanh » thien thanh, hien hanh, dien thanh
tien thanh » tien thinh, tran thanh, den thanh
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
trung va » truong va, trang va, trung ha
dan toan » van toan, dan than, manh 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 thanh) OR (tien thanh)) - thanh trung va ((nhung cong) or (thong cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hien thanh) OR (tien thanh)) - thanh trung va ((nhung cong) OR (thong cong)) dan toan cao*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien thanh) OR (tien thanh)) - thanh trung va ((nhung cong) or (thong cong)) dan toan cao*".