Perhaps you should try some spelling variations:
tranh viet » tran viet, trinh viet, trang viet
viet chung » viet hung, viet phuong, viet thuong
hieu lang » chieu sang, hieu quang, nhieu tang
cong dang » cong dong, cong dung, cong danh
thanh hai » thanh phan, thanh hoa, thanh san
hoi hieu » hoi phieu, hoi tieu, moi hieu
cong dan » cong san, cong tan, huong dan

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 viet chung ((cong dan) or (cong dang)) thanh hai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - canh tranh viet chung ((cong dan) OR (cong dang)) thanh hai*.