Perhaps you should try some spelling variations:
thanh thong » thanh thuong, thanh hong, thanh thang
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
dung dung » ung dung, dung ung, dung dong
thong va » trong va, thong cua, truong va
tai doan » thai doan, tap doan, thi doan
doan tap » toan tap, doan cap, doanh tai
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((chieu sang) or (hieu lang)) - thanh thong va dung dung tai doan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((chieu sang) OR (hieu lang)) - thanh thong va dung dung tai doan tap.
• Adding a wildcard symbol may retrieve word variants: doc ((chieu sang) or (hieu lang)) - thanh thong va dung dung tai doan tap*.