Perhaps you should try some spelling variations:
sang tao » hang tai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
ky sang » ky nang, ky dang, ky tang
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
va danh » va dinh, va dan, va hanh
lai cua » dai cua, hai cua, lai chau
cua tre » cua te, cuu tre, cua triet
va dao » ca dao

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 sang tao boi. hieu ve ((cac du) or (cao duc)) ((va danh) or (va dao)) lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang tao boi. hieu ve ((cac du) OR (cao duc)) ((va danh) OR (va dao)) lai cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang tao boi. hieu ve ((cac du) or (cao duc)) ((va danh) or (va dao)) lai cua tre*.