Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quang » thieu quang, hieu quan, hieu qua
thanh tung » thanh cong
cac chung » cac phuong, cac cong
tung cac » dung cac, vung cac, cung cac
cong ban » cong bang, cong tan, cong dan
cong san » cong tac
than cap » khan cap, thanh lap, thanh cac

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 quang)) - thanh tung cac chung ((cong ban) OR (cong san)) than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu quang)) - thanh tung cac chung ((cong ban) OR (cong san)) than cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu quang)) - thanh tung cac chung ((cong ban) OR (cong san)) than cap".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quang)) - thanh tung cac chung ((cong ban) OR (cong san)) than cap*.