Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu quang » thieu quang, hieu quan, hieu qua
hieu lang » chieu sang, nhieu tang, hieu van
lang cong » dang cong, bang cong, hang cong
dan thanh » dang thanh, danh thanh, ban thanh
thanh lap » thanh san, phan lap, thanh hai
cong dan » cong san, cong tan, huong dan
va lang » va nang, hoa lang

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