Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
hieu lang » chieu sang, hieu quang, nhieu tang
doi hieu » doi chieu, doc hieu, doi hien
cua hang » cua nhung, cua cong, cua ban
cua dang » cua cong, cua ban
tan toan » tan tran, van toan, dan toan
tap toan » tap doan, tap quan, bai toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi hieu lang - hanh tranh ((cua hang) or (cua dang)) cong ((tan toan) or (tap toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi hieu lang - hanh tranh ((cua hang) OR (cua dang)) cong ((tan toan) OR (tap toan)) cau.
• Adding a wildcard symbol may retrieve word variants: doi hieu lang - hanh tranh ((cua hang) or (cua dang)) cong ((tan toan) or (tap toan)) cau*.