Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
tranh cua » doanh cua, manh cua
cua nhung » va nhung
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan tap » toan ban

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) OR (hieu quang)) - canh tranh cua nhung ((cong dan) or (cong san)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu lang) OR (hieu quang)) - canh tranh cua nhung ((cong dan) OR (cong san)) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu lang) OR (hieu quang)) - canh tranh cua nhung ((cong dan) or (cong san)) toan tap".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu lang) OR (hieu quang)) - canh tranh cua nhung ((cong dan) or (cong san)) toan tap*.