Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
thanh trung » thanh tung
nhung cong » dung cong, thong cong, nhung don
tien manh » tien anh, tien thanh, tieng anh
hang cong » dang cong, hang nong, bang cong
san van » tan van, luan van, tran van

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 manh) or (thien thanh)) - thanh trung tam ((nhung cong) or (hang cong)) san van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((tien manh) OR (thien thanh)) - thanh trung tam ((nhung cong) OR (hang cong)) san van ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((tien manh) or (thien thanh)) - thanh trung tam ((nhung cong) or (hang cong)) san van ban*.