Perhaps you should try some spelling variations:
khai luc » khai luoc, khai luan, nhan luc
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
va khai » van khai, va khao, va kha
mai hoi » mai khoi, dai hoi, lai hoi
hai ky » thai ky, hoi ky, hai ly
ma hoi » xa hoi, ma hoa, me hoi
luc va » duc va, tuc va, loc va
vi cau » va cau, di cau, viet cau
ve cau » ke cau, va cau, ve cac
su hai » su tai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su hai ky nang ((ma hoi) or (mai hoi)). hieu va khai luc va hanh ((vi cau) OR (ve cau)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su hai ky nang ((ma hoi) OR (mai hoi)). hieu va khai luc va hanh ((vi cau) OR (ve cau)) treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su hai ky nang ((ma hoi) or (mai hoi)). hieu va khai luc va hanh ((vi cau) OR (ve cau)) treo".
• Adding a wildcard symbol may retrieve word variants: su hai ky nang ((ma hoi) or (mai hoi)). hieu va khai luc va hanh ((vi cau) OR (ve cau)) treo*.