Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, thieu quang
hoc thieu » toc thieu, hoc hien
cao thong » cao thuong, tao thong, giao thong
cao phong » cac phong, co phong, chau phong
cong san » cong tac
gian cac » gian dan, gian cua

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 - thanh trung ((cao thong) OR (cao phong)) ((cong dong) or (cong san)) gian cac~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - thanh trung ((cao thong) OR (cao phong)) ((cong dong) OR (cong san)) gian cac.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu sang - thanh trung ((cao thong) OR (cao phong)) ((cong dong) or (cong san)) gian cac".
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - thanh trung ((cao thong) OR (cao phong)) ((cong dong) or (cong san)) gian cac*.