Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va cach » va cac
dua ban » dia ban, qua ban, mua ban
loi cua » loai cua, hoi cua, doi cua
lai cua » dai cua, hai cua, lai chau
x hoi » xa hoi, o hoi, x ho

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 nang x hoi. hieu va cach ((dua ban) OR (cua ban)) thanh ((loi cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu va cach ((dua ban) OR (cua ban)) thanh ((loi cua) OR (lai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu va cach ((dua ban) OR (cua ban)) thanh ((loi cua) or (lai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu va cach ((dua ban) OR (cua ban)) thanh ((loi cua) or (lai cua)) tre*.