Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, thieu quang
cong quang » luong quang, thong quang, duong quang
hoc thieu » toc thieu, hoc hien
trung va » truong va, trang va, trung ha
cong van » cong vang, song van, cong tan
cong san » cong tac
toan tap » toan ban
va dung » van dung, va duong, vat dung

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 va dung ((((cong van) or (cong san))) or (cong quang)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - thanh trung va dung ((((cong van) OR (cong san))) OR (cong quang)) toan tap.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - thanh trung va dung ((((cong van) or (cong san))) or (cong quang)) toan tap*.