Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cam duc » cam xuc, pham duc, nam duoc
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua
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: thuat sach ky nang ((x hoi) or (x ho)). hieu ve ((cam duc) OR (cao duc)) va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach ky nang ((x hoi) OR (x ho)). hieu ve ((cam duc) OR (cao duc)) va hanh va cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ky nang ((x hoi) or (x ho)). hieu ve ((cam duc) OR (cao duc)) va hanh va cua tre*".