Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
chiet tach » chieu sach
thanh phan » thanh pho, thanh san, thanh toan
quang dung » quang trung, cuong dung
van thanh » ban thanh, van tuan
thanh ban » thanh san, thanh van, thanh bac
cong van » cong vang, cong san, song 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: hoc ((chieu sang) OR (chiet tach)) - thanh phan ((quang dung) OR (ung dung)) cong van thanh ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) or (chiet tach)) - thanh phan ((quang dung) OR (ung dung)) cong van thanh ban~".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (chiet tach)) - thanh phan ((quang dung) OR (ung dung)) cong van thanh ban*.