Perhaps you should try some spelling variations:
tranh cua » doanh cua, manh cua
hoi hieu » hoi phieu, hoi tieu, doi chieu
moi hieu » moi dieu, doi chieu, mot chieu
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) OR (moi 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) OR (moi hieu)))) lang - canh tranh cua ban cong bai toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho hieu) or (((hoi hieu) OR (moi hieu)))) lang - canh tranh cua ban cong bai toan cao".
• Adding a wildcard symbol may retrieve word variants: ((ho hieu) or (((hoi hieu) OR (moi hieu)))) lang - canh tranh cua ban cong bai toan cao*.