Perhaps you should try some spelling variations:
quang thanh » quan thanh, hoang thanh, muong thanh
chieu sang » chieu sach, hieu lang, nhieu tang
chieu xanh » chieu sach, chieu tinh, hieu manh
cong trong » cong thuong, duong trong, cong trinh
trong van » trong cac
van toan » van tuan, van tan, van thanh
toan ban » van ban

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 (chieu xanh)) - tinh quang thanh cong trong van toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((chieu sang) OR (chieu xanh)) - tinh quang thanh cong trong van toan ban.
• Adding a wildcard symbol may retrieve word variants: doc ((chieu sang) or (chieu xanh)) - tinh quang thanh cong trong van toan ban*.