Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
cong hach » cong sach, cong thanh, cong khanh
hach toan » thanh toan, manh toan
cua dung » cua dong, qua dung, cua rung
cua dang » cua cong, cua ban
toan cao » toan ban, toan tap
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 ((cua dung) or (cua dang)) cong hach toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - canh tranh ((cua dung) OR (cua dang)) cong hach toan cao.
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - canh tranh ((cua dung) or (cua dang)) cong hach toan cao*.