Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » dung cong, thong cong, hang cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
van thanh » ban thanh, van tuan
so thiet » soc thiet, hoa thiet, tao thiet
trung va » truong va, trang va, trung ha
ban than » ban thanh, ban hang, ban hanh

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

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