Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
vanh dai » van dai, vanh tai, lanh dao
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan
cua tre » cua te, cuu tre, cua triet
co hai » co hoi, o hai, so hai
co dai » co dan, do dai
va am » va lam, va cam

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: tu sach ky nang ((co hai) OR (co dai)). lieu va am ((thuc va) OR (thuc day)) vanh dai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((co hai) OR (co dai)). lieu va am ((thuc va) or (thuc day)) vanh dai cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((co hai) OR (co dai)). lieu va am ((thuc va) or (thuc day)) vanh dai cua tre*.