Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhieu tang » chieu sang, nhiet nang
hieu lang » chieu sang, hieu quang, hieu van
trung cua » truong cua, trung tuan, trung cap
dung cong » dung trong
cua dung » cua dang, cua dong, qua dung
cong tac » cong ty
than cau » phan cau, than cap, thanh chau
toan cau » toan cao, toan ban, toan tap

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: nho ((hieu lang) OR (nhieu tang)) - thanh trung cua dung cong tac ((than cau) OR (toan cau))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "nho ((hieu lang) OR (nhieu tang)) - thanh trung cua dung cong tac ((than cau) or (toan cau))~".
• Adding a wildcard symbol may retrieve word variants: nho ((hieu lang) OR (nhieu tang)) - thanh trung cua dung cong tac ((than cau) or (toan cau))*.