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 cua » truong cua, trung tuan, trung cap
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
tam than » ban than
than cau » toan cau, phan cau, than cap

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 cua ((hang cong) or (dang cong)) tam than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sang) OR (hieu lang)) - thanh trung cua ((hang cong) OR (dang cong)) tam than cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sang) or (hieu lang)) - thanh trung cua ((hang cong) or (dang cong)) tam than cau*.