Perhaps you should try some spelling variations:
ban hanh » ban hang
nang mai » nang ma, nang tai, lang mai
va thanh » gia thanh, ban thanh, va tinh
su sach » so sach, vu sach
via cua » gia cua, gian cua, giau cua
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
bao bo » bac bo, nao bo, bao bi
ban bo » can bo, ban do, ban co

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang mai hoi. hieu qua ((bao bo) OR (ban bo)) ((ban hanh) or (va thanh)) via cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang mai hoi. hieu qua ((bao bo) OR (ban bo)) ((ban hanh) OR (va thanh)) via cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang mai hoi. hieu qua ((bao bo) OR (ban bo)) ((ban hanh) or (va thanh)) via cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang mai hoi. hieu qua ((bao bo) OR (ban bo)) ((ban hanh) or (va thanh)) via cua tre*.