Perhaps you should try some spelling variations:
ban thanh » ban hanh
ban hang » ngan hang
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
mai hoi » mai khoi, dai hoi, lai hoi
ty nang » ky nang, ty hang, ly nang
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
vi cua » vai cua, di 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 ((ty nang) or (ty xang)) mai hoi. hieu va cam xuc ((ban thanh) or (ban hang)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ty xang)) mai hoi. hieu va cam xuc ((ban thanh) OR (ban hang)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ty xang)) mai hoi. hieu va cam xuc ((ban thanh) or (ban hang)) vi cua tre*.