Perhaps you should try some spelling variations:
ban hanh » ban hang
so danh » do danh, so sanh, so dan
danh ky » hanh ky, dan ky, dang ky
mai hoi » mai khoi, lai hoi, mai doi
dai hoi » dai hoc, dai hai, dai moi
qua cac » cua cac
cac tac » cac toc, cac bac, cac dac
tac ban » tai ban, cac ban, tao ban
doi cua » hoi cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: so danh ky nang ((mai hoi) OR (dai hoi)). hieu qua cac tac ban hanh ((doi cua) or (dai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so danh ky nang ((mai hoi) OR (dai hoi)). hieu qua cac tac ban hanh ((doi cua) OR (dai cua)) triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so danh ky nang ((mai hoi) OR (dai hoi)). hieu qua cac tac ban hanh ((doi cua) or (dai cua)) triet*".