Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
duc van » duc va, duc tan, duc manh
cao duc » dao duc, cao suc, giao duc
hieu va » lieu va, hieu qua
sach ly » sach y, sach lo, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
ly nang » ky nang, ly hang, ly vang
va cao » va cac, va co, va dao
ma hoi » xa hoi, ma hoa, me hoi

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

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