Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, hieu lang
trung cua » truong cua, trung tuan, trung cap
cua dung » cua dang, cua dong, qua dung
cong dan » cong san, huong dan, cong dong
cong tan » cong tac, cong san, cong thanh
than tap » toan tap, han tap, phan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sang) or (hieu qua)) - thanh trung cua dung ((cong dan) OR (cong tan)) than tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu qua)) - thanh trung cua dung ((cong dan) OR (cong tan)) than tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu qua)) - thanh trung cua dung ((cong dan) OR (cong tan)) than tap".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu qua)) - thanh trung cua dung ((cong dan) OR (cong tan)) than tap*.