Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, cao hoc, tao hoi
hieu va » lieu va, hieu qua
va cham » va chat, va tham
tai cua » thai cua, tai cuc, tri cua
co hoi » co hoc, co loi
cua te » cua tu

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 ((cao hoi) OR (co hoi)). hieu va cham ((xuc vay) or (xuc hay)) doanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ((cao hoi) OR (co hoi)). hieu va cham ((xuc vay) OR (xuc hay)) doanh tai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang ((cao hoi) OR (co hoi)). hieu va cham ((xuc vay) or (xuc hay)) doanh tai cua te*".