Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, te sach, tu cach
cac duc » cac du, cao duc, cac dac
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
su sach » so sach, vu sach
ve cac » va cac, vien cac

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) or (su sach)) ky lang xa hoi. hieu ve cac duc ((van hanh) or (ban thanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky lang xa hoi. hieu ve cac duc ((van hanh) OR (ban thanh)) hai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky lang xa hoi. hieu ve cac duc ((van hanh) or (ban thanh)) hai cua tre*.