Perhaps you should try some spelling variations:
thanh trung » thanh tung
chiet tach » chieu sach
hieu lang » chieu sang, hieu quang, nhieu tang
cua thong » cua thuong, cua khong, suat thong
cua tong » cua cong, cua dong, cua nong
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap

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: ho ((hieu lang) OR (chiet tach)) - thanh trung ((cua thong) OR (cua tong)) cong dan than cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu lang) or (chiet tach)) - thanh trung ((cua thong) OR (cua tong)) cong dan than cau~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu lang) or (chiet tach)) - thanh trung ((cua thong) OR (cua tong)) cong dan than cau*.