Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
cach dung » sach dung, cach mang, tac dung
cua nhung » va nhung
dung cua » dung luan, dung cho
cong dan » cong san, cong tan, huong dan
phan dau » phan tu
hang dau » hang va, hang tai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((hieu lang) or (hieu qua)) - cach dung cua nhung cong dan ((phan dau) or (hang dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((hieu lang) OR (hieu qua)) - cach dung cua nhung cong dan ((phan dau) OR (hang dau)).
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (hieu qua)) - cach dung cua nhung cong dan ((phan dau) or (hang dau))*.