Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu xanh » chieu xanh, hieu manh, thien anh
chieu sang » chieu sach, chieu xanh, hieu lang
nhung cong » dung cong, thong cong, hang cong
trung cua » truong cua, trung tuan, trung cap
cua nhung » va nhung
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: hoc ((thieu xanh) or (chieu sang)) - thanh trung cua nhung cong ((dan toan) OR (dan than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu sang)) - thanh trung cua nhung cong ((dan toan) OR (dan than)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) or (chieu sang)) - thanh trung cua nhung cong ((dan toan) OR (dan than)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) or (chieu sang)) - thanh trung cua nhung cong ((dan toan) OR (dan than)) cau*.