Perhaps you should try some spelling variations:
thong cong » trong cong, tong cong, thong thong
nhung cong » dung cong, hang cong, nhung don
hieu lang » chieu sang, hieu quang, nhieu tang
tranh cua » doanh cua, manh cua
toan cau » toan cao, toan ban, toan tai
toan tap » toan ban
ho hieu » ho chieu, hoi hieu, nho 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 lang - canh tranh cua ((nhung cong) OR (thong cong)) tan ((toan cau) OR (toan tap))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - canh tranh cua ((nhung cong) or (thong cong)) tan ((toan cau) OR (toan tap))~".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - canh tranh cua ((nhung cong) or (thong cong)) tan ((toan cau) OR (toan tap))*.