Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
vai cua » dai cua, hai cua, lai cua
cac tu » cac thu, cach tu, tac tu
va dan » ca dan, va dao, va dau
vi cua » di cua
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 ve ((cac tu) or (cac du)) va dan ((vi cua) OR (vai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu ve ((cac tu) OR (cac du)) va dan ((vi cua) OR (vai cua)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu ve ((cac tu) or (cac du)) va dan ((vi cua) OR (vai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu ve ((cac tu) or (cac du)) va dan ((vi cua) OR (vai cua)) tre*.