Perhaps you should try some spelling variations:
tranh cua » doanh cua, manh cua
hoi hieu » hoi phieu, hoi tieu, moi hieu
ban cong » bang cong, van cong, phan cong
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan cao » toan ban, toan tap
ho hieu » ho chieu, nho hieu, co hieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho hieu) or (hoi hieu)) lang - canh tranh cua ban cong bai toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho hieu) OR (hoi hieu)) lang - canh tranh cua ban cong bai toan cao.
• Adding a wildcard symbol may retrieve word variants: ((ho hieu) or (hoi hieu)) lang - canh tranh cua ban cong bai toan cao*.