Perhaps you should try some spelling variations:
doan vai » doan va, doan van, doan hai
vai cua » dai cua, hai cua, lai cua
va doan » va doanh, van doan, va dan
cach tu » cach thuc
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky

You may be able to get more results by adjusting your search query.

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