Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
thanh trung » thanh tung
thuong cong » thong cong, thuong dong, truong cong
thieu sang » chieu sang, thieu quang, hieu lang
thuong con » thuong dong, truong cong, thong cong
trung cua » truong cua, trung tuan, trung cap
dan than » dan chan, ban than, van than
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: hoc ((thieu sang) OR (thieu khang)) - thanh trung cua ((thuong cong) or (thuong con)) dan than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - thanh trung cua ((thuong cong) OR (thuong con)) dan than cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) OR (thieu khang)) - thanh trung cua ((thuong cong) or (thuong con)) dan than cap".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) OR (thieu khang)) - thanh trung cua ((thuong cong) or (thuong con)) dan than cap*.