Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
dang luan » dung luan, hang luan, dan luan
tang luan » dung luan
dung cong » dung trong
cong tang » cong thang, cong tan, cong lang
doc hieu » toc thieu, hoc thieu, hoc hien
tang van » dang van, hoang van, trong van

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