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 can » trong canh, trong chan, trong cac
cong cong » cong dong, trong cong, dung cong
can cong » cac cong, cao cong, van cong
cong san » cong tac
san toan » van toan, dan toan, manh toan
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: hoc ((chieu sang) or (hieu lang)) - thanh trong can cong cong san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - thanh trong can cong cong san toan ban.
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) or (hieu lang)) - thanh trong can cong cong san toan ban*.