Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, cao hoc, tao hoi
hieu ve » hieu va, hieu van
xuc van » luc van, xuc ban, thuc van
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, co loi
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: tu sach ky nang ((cao hoi) or (co hoi)). 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: tu sach ky nang ((cao hoi) OR (co hoi)). hieu ve cam ((xuc van) OR (duc van)) hanh di cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((cao hoi) or (co hoi)). hieu ve cam ((xuc van) or (duc van)) hanh di cua tre*.