Perhaps you should try some spelling variations:
nhung cong » dung cong, hang cong, nhung don
hieu quang » thieu quang, hieu qua, diep quang
thong cong » trong cong, tong cong, thong thong
hieu quan » hieu qua, lieu quan, thien quan
tranh van » tran van, trinh van, thanh van
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 van ((nhung cong) OR (thong 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 van ((nhung cong) OR (thong 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 van ((nhung cong) OR (thong cong)) co phan dau".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quang) or (hieu quan)) - canh tranh van ((nhung cong) OR (thong cong)) co phan dau*.