Perhaps you should try some spelling variations:
thieu nien » thien nhien
toc sach » hoc sach, doc sach, thuoc sach
nien cac » vien cac, dien cac, bien cac
cac thuc » cach thuc, cac thu, can thuc
thuc day » thuc dan, thuc vat
day hang » dat hang, dai hang, day nang
hang dau » hang va, hang tai
nang xa » lang xa, nang ma, mang xa
dau cua » dai cua, day cua, cau cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y ((nang xa) or (nang x)) hoi. thieu nien cac thuc day hang dau cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((nang xa) OR (nang x)) hoi. thieu nien cac thuc day hang dau cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y ((nang xa) or (nang x)) hoi. thieu nien cac thuc day hang dau cua tre*.