Perhaps you should try some spelling variations:
hanh doanh » hang doanh, chinh doanh, doanh doanh
canh doanh » chinh doanh, doanh doanh, kinh doanh
hieu lang » chieu sang, hieu quang, nhieu tang
cua thong » cua thuong, cua khong, cua tong
hoc hieu » hoc thieu, hoc hien, doc hieu
cong dan » cong san, cong tan, cong dong

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

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