Perhaps you should try some spelling variations:
nhung phuong » dung phuong, nhu phuong, truong phuong
nhung huong » nhung tuong, nhung cong, nhung dung
hieu quang » thieu quang, hieu quan, hieu qua
tranh cua » doanh cua, manh cua
doc hieu » toc thieu, hoc thieu, hoc hien
toan cao » toan ban
toan tap » toan ban

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 quang - canh tranh cua ((nhung huong) or (nhung phuong)) dan ((toan cao) OR (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu quang - canh tranh cua ((nhung huong) OR (nhung phuong)) dan ((toan cao) OR (toan tap))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu quang - canh tranh cua ((nhung huong) or (nhung phuong)) dan ((toan cao) OR (toan tap))*".