Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu qua, diep quang
nhung dong » nhung don, nhung dung, nhung bong
nhung cong » dung cong, thong cong, hang cong
hieu quan » hieu qua, lieu quan, thien quan
tranh va » tranh van, trang va, trinh va
phan dau » phan tu, hang dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu quang) or (hieu quan)) - canh tranh va ((nhung dong) OR (nhung cong)) co phan dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu quang) OR (hieu quan)) - canh tranh va ((nhung dong) OR (nhung cong)) co phan dau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quang) or (hieu quan)) - canh tranh va ((nhung dong) OR (nhung cong)) co phan dau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quang) or (hieu quan)) - canh tranh va ((nhung dong) OR (nhung cong)) co phan dau*.