Perhaps you should try some spelling variations:
thanh trong » thanh trung, tranh trong, hanh trong
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
trong van » trong cac
cong cong » cong dong, trong cong, dung cong
van cong » van dong, van phong, phan cong
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.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) or (hieu lang)) - thanh trong van cong cong san van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - thanh trong van cong cong san van ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (hieu lang)) - thanh trong van cong cong san van ban*.