Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
tranh cua » doanh cua, manh cua
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
cua dung » cua dang, cua dong, qua dung
dan than » dan chan, ban than, dan toan
van than » van thanh, van thang, van tuan

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 xanh - canh tranh cua dung cong ((dan than) or (van than)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - canh tranh cua dung cong ((dan than) OR (van than)) ban.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh tranh cua dung cong ((dan than) or (van than)) ban*.