Perhaps you should try some spelling variations:
ban hanh » ban hang
van hanh » van thanh, van anh, van ban
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
hai cua » thai cua, dai cua, hoi cua
cam duc » cam xuc, cao duc, pham duc
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va
xang xa » lang xa, mang xa, ang xa
cua tre » cua te, cuu tre, cua triet

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 ty xang xa hoi. ((hieu ve) or (hieu van)) cam duc ((van hanh) OR (ban hanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang xa hoi. ((hieu ve) OR (hieu van)) cam duc ((van hanh) OR (ban hanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty xang xa hoi. ((hieu ve) or (hieu van)) cam duc ((van hanh) OR (ban hanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang xa hoi. ((hieu ve) or (hieu van)) cam duc ((van hanh) OR (ban hanh)) hai cua tre*.