Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
hanh dung » thanh dung, hanh dong, manh dung
dung song » dung dong, vung song, dong song
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
anh dung » anh dong, anh huong, sach dung
van tan » van tuan, van ban, van tai
tan tap » toan tap, han tap, tan tat

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 - ((hanh dung) OR (anh dung)) luan ((dung song) or (dung cong)) van tan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - ((hanh dung) OR (anh dung)) luan ((dung song) OR (dung cong)) van tan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - ((hanh dung) OR (anh dung)) luan ((dung song) or (dung cong)) van tan tap".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - ((hanh dung) OR (anh dung)) luan ((dung song) or (dung cong)) van tan tap*.