Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu sang » chieu sang, hieu quang, nhieu tang
hieu lang » chieu sang, hieu quang, nhieu tang
trung cao » truong cao, trung cap, trung co
trong ban » trong san, trong quan, trong cac
trong tan » trong quan, trong cac, trong ca
cao dung » cao dang, cao dong, cao ung
pha cac » phan cac, phap cac, pha cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sang) or (hieu lang)) - thanh trung cao dung ((trong ban) or (trong tan)) pha cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - thanh trung cao dung ((trong ban) OR (trong tan)) pha cac.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu lang)) - thanh trung cao dung ((trong ban) or (trong tan)) pha cac*.