Perhaps you should try some spelling variations:
thieu khang » chieu khong, thieu quang
truong quan » trong quan, thong quan, luong quan
thieu sang » chieu sang, thieu quang, hieu lang
truong cua » truong ca, truong cao, huong cua
hang cong » dang cong, hang nong, bang cong
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan cao » toan ban, toan tap

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sang) OR (thieu khang)) - hanh ((truong cua) OR (truong quan)) hang cong san toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sang) or (thieu khang)) - hanh ((truong cua) OR (truong quan)) hang cong san toan cao~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sang) or (thieu khang)) - hanh ((truong cua) OR (truong quan)) hang cong san toan cao*.