Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hanh tranh » canh tranh, hanh trang, lanh tranh
cong huong » cong thuong, cong luong, cong hung
theo hieu » theo chieu, theo tieu, thien hieu
hieu lang » chieu sang, hieu quang, nhieu tang
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo hieu lang - ((hanh tranh) or (hanh trinh)) cua cong huong ((dan toan) OR (dan than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo hieu lang - ((hanh tranh) OR (hanh trinh)) cua cong huong ((dan toan) OR (dan than)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo hieu lang - ((hanh tranh) or (hanh trinh)) cua cong huong ((dan toan) OR (dan than)) cao".
• Adding a wildcard symbol may retrieve word variants: theo hieu lang - ((hanh tranh) or (hanh trinh)) cua cong huong ((dan toan) OR (dan than)) cao*.