Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
xuc van » duc van, luc van, vuc van
sach ly » sach y, sach lo, sach ty
lai hoi » dai hoi, lai hoa, lai roi
mai hoi » mai khoi, dai hoi, mai doi
ly nang » ky nang, ly hang, ly vang
cua duc » cua tuc, cua nuoc, cua quoc
va cam » va cham, va cac, va cai
va cao » va cac, va co, va dao
vi cua » vai cua, di cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ly nang ((mai hoi) or (lai hoi)). hieu ((va cam) OR (va cao)) xuc van hanh vi cua duc~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang ((mai hoi) OR (lai hoi)). hieu ((va cam) OR (va cao)) xuc van hanh vi cua duc.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ly nang ((mai hoi) or (lai hoi)). hieu ((va cam) OR (va cao)) xuc van hanh vi cua duc".
• Adding a wildcard symbol may retrieve word variants: su sach ly nang ((mai hoi) or (lai hoi)). hieu ((va cam) OR (va cao)) xuc van hanh vi cua duc*.