Perhaps you should try some spelling variations:
thanh trung » thanh tung
thanh duong » thanh huong, thanh cuong, thanh vuong
theo chieu » theo tieu, ho chieu, theo chu
thang dung » thong dung, thanh dung, thuong dung
mot chieu » doi chieu, ho chieu
trung cua » truong cua, trung tuan, trung cap
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: ((mot chieu) OR (theo chieu)) xanh - thanh trung cua ((thang dung) OR (thanh duong)) tai toan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((mot chieu) or (theo chieu)) xanh - thanh trung cua ((thang dung) OR (thanh duong)) tai toan tap~".
• Adding a wildcard symbol may retrieve word variants: ((mot chieu) or (theo chieu)) xanh - thanh trung cua ((thang dung) OR (thanh duong)) tai toan tap*.