Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
cac tu » cac thu, cach tu, tac tu
va dan » va dao, va dau, va dap
ca dan » cac dan, ca dao
vi cua » vai cua, di cua

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 x ho. hieu ve ((cac tu) or (cac du)) ((va dan) OR (ca dan)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang x ho. hieu ve ((cac tu) OR (cac du)) ((va dan) OR (ca dan)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang x ho. hieu ve ((cac tu) or (cac du)) ((va dan) OR (ca dan)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang x ho. hieu ve ((cac tu) or (cac du)) ((va dan) OR (ca dan)) vi cua tre*.