Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cac lop » cac hop, cac loai
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
cac lo » cac co, cac bo, cac ho
va cua » va chua, via cua, ca cua
x hoi » xa hoi, o hoi, x ho

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. hieu ve ((cac lo) OR (cac lop)) va hanh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang x hoi. hieu ve ((cac lo) OR (cac lop)) va hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang x hoi. hieu ve ((cac lo) OR (cac lop)) va hanh va cua tre*.