Perhaps you should try some spelling variations:
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va thanh, dao hanh
hai cua » thai cua, dai cua, hoi cua
va danh » va dinh, va dan, dia danh
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
ve cam » ve cham, ve cac, va cam
ma hoi » mai hoi, xa hoi, ma hoa

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