Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hanh tranh » canh tranh, hanh trinh, hanh trang
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, nhieu tang, hieu van
tranh cua » doanh cua, manh cua
cua nhung » va nhung
dan than » dan chan, van than, dan toan
ban than » ban thanh, van thanh, ban hang

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi ((hieu lang) or (hieu quang)) - hanh tranh cua nhung cong ((dan than) OR (ban than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu lang) OR (hieu quang)) - hanh tranh cua nhung cong ((dan than) OR (ban than)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi ((hieu lang) or (hieu quang)) - hanh tranh cua nhung cong ((dan than) OR (ban than)) cao".
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu lang) or (hieu quang)) - hanh tranh cua nhung cong ((dan than) OR (ban than)) cao*.