Perhaps you should try some spelling variations:
hanh dong » anh dong
luan dung » lan dung, luan dong, luan hung
dung cong » dung trong
cong vang » cong lang, cong quang, cong ngang
vang toan » van toan, dang toan, quang toan
doc hieu » toc thieu, hoc thieu
toan cao » toan ban, toan tap
ha dong » hoat dong, van dong

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