Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
qua cham » qua hai, qua cac, va cham
dai hoi » dai hoc, dai hai, dai moi
sach ky » sac ky, sach y, sach ty
cham lo » cham o, cam lo, cham soc
tai hoi » tai khoi, tai hai, tai hoe
va danh » va dinh, va dan, va hanh
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: thu sach ky nang ((tai hoi) OR (dai hoi)). hieu qua cham lo ((ban hanh) or (va danh)) tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((tai hoi) OR (dai hoi)). hieu qua cham lo ((ban hanh) OR (va danh)) tri cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((tai hoi) OR (dai hoi)). hieu qua cham lo ((ban hanh) or (va danh)) tri cua tre*".