Perhaps you should try some spelling variations:
nhanh dong » hanh dong, nhanh chong, anh dong
chuan long » chua dong, quan long, thuan cong
hieu lang » chieu sang, hieu quang, nhieu tang
chat long » chat luong, hai long, ha long
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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 lang - nhanh dong ((chuan long) or (chat long)) cong dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu lang - nhanh dong ((chuan long) OR (chat long)) cong dan than cau.
• Adding a wildcard symbol may retrieve word variants: doc hieu lang - nhanh dong ((chuan long) or (chat long)) cong dan than cau*.