Perhaps you should try some spelling variations:
thieu sang » thieu khang, thieu quang, hieu lang
chieu sang » chieu sach, chieu xanh, hieu lang
thanh dung » thanh duong, thanh tung, thanh hung
nhung cong » dung cong, thong cong, nhung don
tinh khang » tinh khong, trinh khung, tinh quang
hang cong » dang cong, hang nong, bang cong
khang lap » phan lap, thanh lap, sang lap

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 (chieu sang)) - thanh dung va ((nhung cong) or (hang cong)) tinh khang lap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (chieu sang)) - thanh dung va ((nhung cong) OR (hang cong)) tinh khang lap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) OR (chieu sang)) - thanh dung va ((nhung cong) or (hang cong)) tinh khang lap".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) OR (chieu sang)) - thanh dung va ((nhung cong) or (hang cong)) tinh khang lap*.