Perhaps you should try some spelling variations:
thanh dung » thanh duong, thanh tung, thanh dong
thanh hung » thanh huong, thanh tung, thanh trung
hieu lang » chieu sang, hieu quang, nhieu tang
hanh dung » anh dung, hanh dong, manh dung
cua thong » cua thuong, cua khong, cua tong
thong dan » thong van, tuong dan, thong den
doi hieu » doi chieu, doc hieu, doi hien
dan van » dang van, doan van, dao 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: doi hieu lang - ((((thanh dung) OR (hanh dung))) OR (thanh hung)) cua thong thong dan van ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi hieu lang - ((((thanh dung) OR (hanh dung))) or (thanh hung)) cua thong thong dan van ban~".
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - ((((thanh dung) OR (hanh dung))) or (thanh hung)) cua thong thong dan van ban*.