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