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

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 quang)) - thanh trung cao dong ((trong ban) or (trong san)) pha cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu quang)) - thanh trung cao dong ((trong ban) OR (trong san)) pha cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu quang)) - thanh trung cao dong ((trong ban) or (trong san)) pha cau*.