Perhaps you should try some spelling variations:
thanh trung » thanh tung
theo chieu » theo tieu, theo chu, thi chieu
cua thang » cua hang, xua thang, cua thuong
cua thanh » gia thanh, va thanh, ha thanh
luong tai » dung tai, luong va
ho chieu » hoc thieu, doi chieu, mot chieu
tai toan » bai toan, tap toan, tai tuan
toan tap » toan ban

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

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