Perhaps you should try some spelling variations:
cong thanh » dong thanh, cong trinh, cong tan
hieu lang » chieu sang, hieu quang, nhieu tang
canh manh » canh tranh, cach mang, van manh
lanh manh » lanh tranh, lan anh, van manh
cua nhung » va nhung
cong tac » cong ty
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 manh) OR (lanh manh)) cua nhung ((cong tac) or (cong thanh)) van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho hieu lang - ((canh manh) OR (lanh manh)) cua nhung ((cong tac) OR (cong thanh)) van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho hieu lang - ((canh manh) OR (lanh manh)) cua nhung ((cong tac) or (cong thanh)) van ban".
• Adding a wildcard symbol may retrieve word variants: ho hieu lang - ((canh manh) OR (lanh manh)) cua nhung ((cong tac) or (cong thanh)) van ban*.