Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu lang » chieu sang, hieu quang, nhieu tang
hoi hieu » hoi phieu, hoi tieu, moi hieu
tranh va » tranh van, trang va, trinh va
cong san » cong tac
toan cau » toan cao, toan tai
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu lang - canh tranh va nhung cong san ((toan cau) or (((toan tap) OR (toan ban))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - canh tranh va nhung cong san ((toan cau) OR (((toan tap) OR (toan ban)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi hieu lang - canh tranh va nhung cong san ((toan cau) or (((toan tap) OR (toan ban))))".
• Adding a wildcard symbol may retrieve word variants: hoi hieu lang - canh tranh va nhung cong san ((toan cau) or (((toan tap) OR (toan ban))))*.