Perhaps you should try some spelling variations:
hieu xanh » chieu xanh, hieu manh, hieu nganh
hanh dong » anh dong, ha dong
luan dung » lan dung, luan dong, luan hung
dung cong » dung trong
vang toan » van toan, dang toan, quang toan
dang tran » dang thanh, quang tran, hoang tran
doc hieu » toc thieu, hoc thieu, hoc hien

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 dong) or (hoat dong)) luan dung cong ((vang toan) or (dang tran)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - ((hanh dong) OR (hoat dong)) luan dung cong ((vang toan) OR (dang tran)) cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - ((hanh dong) or (hoat dong)) luan dung cong ((vang toan) or (dang tran)) cao*.