Perhaps you should try some spelling variations:
tranh viet » tran viet, trinh viet, trang viet
viet chung » viet hung, viet phuong, viet thuong
thanh phan » thanh pho, thanh san, thanh toan
hieu lang » chieu sang, hieu quang, nhieu tang
cong lang » cong vang, cong luong, cong quang
cong tan » cong tac, cong san, cong thanh
ho hieu » ho chieu, hoi hieu, nho 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 lang - canh tranh viet chung ((cong tan) or (cong lang)) thanh phan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - canh tranh viet chung ((cong tan) OR (cong lang)) thanh phan*.