Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, nhieu tang, hieu van
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung
cong san » cong tac
phan cac » nhan cach, phan lap, phan van
phan dau » phan tu, hang dau

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

• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu lang) OR (hieu quang)) - thanh trung cua nhung cong san ((phan cac) OR (phan dau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu lang) OR (hieu quang)) - thanh trung cua nhung cong san ((phan cac) or (phan dau))~".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu lang) OR (hieu quang)) - thanh trung cua nhung cong san ((phan cac) or (phan dau))*.