Perhaps you should try some spelling variations:
thanh trung » thanh tung
thiet tach » thien hach, thuat tach
chiet tach » chieu sach
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
trung vap » trung cap, trung va, trung van
ban thanh » ban hanh, ban hang
thanh cap » thanh lap, hanh cap, than cap

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thiet tach) OR (chiet tach)) - thanh trung vap ((nhung cong) or (thong cong)) ban thanh cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thiet tach) OR (chiet tach)) - thanh trung vap ((nhung cong) OR (thong cong)) ban thanh cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thiet tach) OR (chiet tach)) - thanh trung vap ((nhung cong) or (thong cong)) ban thanh cap".
• Adding a wildcard symbol may retrieve word variants: hoc ((thiet tach) OR (chiet tach)) - thanh trung vap ((nhung cong) or (thong cong)) ban thanh cap*.