Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » thong cong, hang cong, nhung don
hieu manh » chieu xanh, hieu nganh, dieu hanh
hieu lang » chieu sang, hieu quang, nhieu tang
dung cong » dung trong
trung va » truong va, trang va, trung ha
tan phan » toan phan, than phan, van phan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu manh) or (hieu lang)) - thanh trung va ((nhung cong) or (dung cong)) tan phan tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu manh) OR (hieu lang)) - thanh trung va ((nhung cong) OR (dung cong)) tan phan tu.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu manh) or (hieu lang)) - thanh trung va ((nhung cong) or (dung cong)) tan phan tu*.