Perhaps you should try some spelling variations:
sach ty » sach y, sach tu, sach thu
sach ky » sac ky, sach y, sach kem
van bao » van ban, van dao
van hac » van hoc, van ha, van hai
thuc va » thuc vat, thuc dan, thuc day
dao dai » dat dai, dao dan, tao dai
cua tre » cua te, cuu tre, cua triet
va dao » ca dao
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: thu ((sach ky) or (sach ty)) nang x hoi. hieu ((van bao) or (van hac)) thuc va dao dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sach ty)) nang x hoi. hieu ((van bao) OR (van hac)) thuc va dao dai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sach ty)) nang x hoi. hieu ((van bao) or (van hac)) thuc va dao dai cua tre*.