Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu sang » chieu sang, hieu lang, hieu quang
doan phan » doanh phan, toan phan, doanh nhan
doc hieu » toc thieu, hoc thieu, hoc hien
tranh va » tranh van, trang va, trinh va
dan phan » dan chan, dam phan, dan than
van phan » van phong, van thanh, luan phan

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 sang - canh tranh va nhung cong ((((dan phan) or (van phan))) or (doan phan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sang - canh tranh va nhung cong ((((dan phan) OR (van phan))) OR (doan phan)) cau.
• Adding a wildcard symbol may retrieve word variants: doc hieu sang - canh tranh va nhung cong ((((dan phan) or (van phan))) or (doan phan)) cau*.