Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu tinh » trieu tinh, lieu tinh, chau tinh
hieu manh » chieu xanh, hieu nganh, dieu hanh
trong bai » trong ban, thong bai, trong hai
cua dung » cua dang, cua dong, cua rung
qua dung » quang dung, su dung, qua song
bai toan » bai tap
toan ban » van 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 ((hieu manh) OR (chieu tinh)) - thanh trung ((cua dung) OR (qua dung)) trong bai toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu manh) or (chieu tinh)) - thanh trung ((cua dung) OR (qua dung)) trong bai toan ban~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu manh) or (chieu tinh)) - thanh trung ((cua dung) OR (qua dung)) trong bai toan ban*.