Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
sach ky » sac ky, sach y, sach ty
cam duc » cam xuc, pham duc, nam duoc
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
vai cua » dai cua, hai cua, lai cua
cua te » cua tu
x hoi » xa hoi, o hoi, 5 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 ky nang ((x hoi) OR (x ho)). hieu van ((cam duc) or (cao duc)) va hanh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((x hoi) OR (x ho)). hieu van ((cam duc) OR (cao duc)) va hanh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((x hoi) OR (x ho)). hieu van ((cam duc) or (cao duc)) va hanh vai cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((x hoi) OR (x ho)). hieu van ((cam duc) or (cao duc)) va hanh vai cua te*.