Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, nhung don
tranh cua » doanh cua, manh cua
hang cong » dang cong, hang nong, bang cong
toan tai » toan tap, doanh tai, toan ban
toan cao » toan ban, toan tap
ho hieu » ho chieu, hoi hieu, nho hieu

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 - canh tranh cua ((nhung cong) or (hang cong)) dan ((toan tai) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu quang - canh tranh cua ((nhung cong) OR (hang cong)) dan ((toan tai) OR (toan cao)).
• Adding a wildcard symbol may retrieve word variants: ho hieu quang - canh tranh cua ((nhung cong) or (hang cong)) dan ((toan tai) or (toan cao))*.