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 va » tranh van, trang va, trinh va
cong san » cong tac
san van » tan van, luan van, tran van

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

• Performing a fuzzy search may retrieve terms with similar spellings: nho ((hieu lang) or (hieu quang)) - hanh tranh va nhung cong san van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: nho ((hieu lang) OR (hieu quang)) - hanh tranh va nhung cong san van ban.
• Adding a wildcard symbol may retrieve word variants: nho ((hieu lang) or (hieu quang)) - hanh tranh va nhung cong san van ban*.