Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
tranh cua » doanh cua, manh cua
cua nhung » va nhung
hoi hieu » hoi phieu, hoi tieu, moi hieu
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban
ho hieu » ho chieu, nho hieu, vo hieu
co hieu » cao hieu, doc hieu

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) OR (co hieu))) OR (hoi hieu)) lang - canh tranh cua nhung cong bai toan ban~.
• Adding a wildcard symbol may retrieve word variants: ((((ho hieu) or (co hieu))) or (hoi hieu)) lang - canh tranh cua nhung cong bai toan ban*.