Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sang » chieu sang, thieu khang, thieu quang
thong cong » trong cong, tong cong, thong thong
hoc thieu » toc thieu, hoc hien
va thong » va thuong, va phuong, he thong
san toan » dan toan, manh toan, xuan toan
van toan » van tuan, van tan, van thanh

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