Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
hanh tang » hanh trang, anh tang, hanh mang
cua nhung » va nhung
tang cua » mang cua, hang cua, tang luan
dan than » dan chan, ban than, dan toan
van than » van thanh, van thang, van tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi ((hieu lang) or (hieu qua)) - hanh tang cua nhung cong ((dan than) or (van than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi ((hieu lang) OR (hieu qua)) - hanh tang cua nhung cong ((dan than) OR (van than)) cao.
• Adding a wildcard symbol may retrieve word variants: hoi ((hieu lang) or (hieu qua)) - hanh tang cua nhung cong ((dan than) or (van than)) cao*.