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
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap
va hanh » van hanh, va thanh, va danh
va lang » va nang, hoa lang

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 hanh) or (va lang)) cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu sang - thanh trung ((va hanh) OR (va lang)) cong dan toan cau*.