Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cao thuc » cao thuoc, bao thuc, can thuc
danh hai » dang hai, lanh hai, manh hai
ty nang » ky nang, ty xang, ty hang
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
hai cua » thai cua, dai cua, hoi cua
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va 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: ((te sach) or (toc sach)) ty nang x hoi. lieu va cao thuc va danh hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty nang x hoi. lieu va cao thuc va danh hai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ty nang x hoi. lieu va cao thuc va danh hai cua tre*.