Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, thieu quang
dung chung » dung cong, dung ung, dung trung
hoc thieu » toc thieu, hoc hien
doan toan » doan tuan, doanh hoan, doan trang
trung va » truong va, trang va, trung ha
dan toan » van toan, dan than, manh toan
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 chung ((doan toan) or (dan toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - thanh trung va dung chung ((doan toan) OR (dan toan)) cau.
• Adding a wildcard symbol may retrieve word variants: hoc thieu sang - thanh trung va dung chung ((doan toan) or (dan toan)) cau*.