Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, hieu lang
hoc chieu » hoc thieu, ho chieu, hoc hien
trung va » truong va, trang va, trung ha
cong ban » cong bang, cong san, cong dan
cong tan » cong san, cong thanh, cong ty
cong tac » cong ty
than cau » toan cau, phan cau, than cap
va dung » van dung, va duong, vat dung

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: hoc chieu sang - thanh trung va dung ((((cong ban) OR (cong tan))) OR (cong tac)) than cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chieu sang - thanh trung va dung ((((cong ban) OR (cong tan))) or (cong tac)) than cau~".
• Adding a wildcard symbol may retrieve word variants: hoc chieu sang - thanh trung va dung ((((cong ban) OR (cong tan))) or (cong tac)) than cau*.