Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
cua thong » cua thuong, cua khong, cua tong
tranh cua » doanh cua, manh cua
hieu luc » hieu luat
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan tap » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((hieu luc) or (hieu qua)) - canh tranh cua thong cong san toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu luc) OR (hieu qua)) - canh tranh cua thong cong san toan tap.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu luc) or (hieu qua)) - canh tranh cua thong cong san toan tap*.