Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quang » thieu quang, hieu quan, hieu qua
thong cong » trong cong, tong cong, thong thong
trung va » truong va, trang va, trung ha
va thong » va thuong, va phuong, he thong
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu sang) or (hieu quang)) - thanh trung va thong cong ((dan toan) or (dan than)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu quang)) - thanh trung va thong cong ((dan toan) OR (dan than)) tap.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quang)) - thanh trung va thong cong ((dan toan) or (dan than)) tap*.