Perhaps you should try some spelling variations:
nhieu tang » chieu sang, nhiet nang
nhanh mang » nhanh lang, hanh mang, nhanh quang
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, hieu van
cua nhung » va nhung
anh tang » anh bang, anh dang, anh nang
cong san » cong tac
san van » tan van, luan van, tran van

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

• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu lang) OR (nhieu tang)) - ((anh tang) OR (nhanh mang)) cua nhung cong san van ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu lang) OR (nhieu tang)) - ((anh tang) or (nhanh mang)) cua nhung cong san van ban~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu lang) OR (nhieu tang)) - ((anh tang) or (nhanh mang)) cua nhung cong san van ban*.