Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu xanh » hieu manh, thien anh, thien danh
chieu xanh » chieu sach, chieu sang, chieu tinh
trung cua » truong cua, trung tuan, trung cap
cua trong » cua truong, cua trung, qua trong
tan toan » tan tran, tap toan, van toan
bai toan » bai tap

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 xanh)) - thanh trung cua trong cong ((tan toan) or (bai toan)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu xanh) OR (chieu xanh)) - thanh trung cua trong cong ((tan toan) OR (bai toan)) tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu xanh) OR (chieu xanh)) - thanh trung cua trong cong ((tan toan) or (bai toan)) tap".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu xanh) OR (chieu xanh)) - thanh trung cua trong cong ((tan toan) or (bai toan)) tap*.