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
xuc van » luc van, vuc van, xuc ban
duc van » duc va, duc tan, duc manh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
co hoi » co hoc
ve cam » ve cham, ve cac, va cam
di cua » dai cua, doi cua, de cua

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 ((co hoi) or (co loi)). hieu ve cam ((xuc van) or (duc van)) hanh di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((co hoi) OR (co loi)). hieu ve cam ((xuc van) OR (duc van)) hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ((co hoi) or (co loi)). hieu ve cam ((xuc van) or (duc van)) hanh di cua tre*.