Perhaps you should try some spelling variations:
doanh thanh » doanh nhan, dinh thanh, dong thanh
nhung cong » dung cong, thong cong, hang cong
danh thanh » dinh thanh, dang thanh, nhanh thanh
hieu sang » chieu sang, hieu lang, hieu quang
tranh cua » manh cua
doanh cua » doanh luan
doc hieu » toc thieu, hoc thieu, hoc hien

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 sang - canh ((tranh cua) OR (doanh cua)) nhung cong ((doanh thanh) or (danh thanh)) tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - canh ((tranh cua) OR (doanh cua)) nhung cong ((doanh thanh) OR (danh thanh)) tu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu sang - canh ((tranh cua) OR (doanh cua)) nhung cong ((doanh thanh) or (danh thanh)) tu".
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - canh ((tranh cua) OR (doanh cua)) nhung cong ((doanh thanh) or (danh thanh)) tu*.