Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
trung va » truong va, trang va, trung ha
truc va » thuc va, thuc vat
tai cua » thai cua, tai cuc, tri cua
han tai » hang tai, nhan tai, van tai
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (toc sach)) ky lang xa hoi. lieu va cao ((truc va) OR (trung va)) han tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) ky lang xa hoi. lieu va cao ((truc va) OR (trung va)) han tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (toc sach)) ky lang xa hoi. lieu va cao ((truc va) OR (trung va)) han tai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) ky lang xa hoi. lieu va cao ((truc va) OR (trung va)) han tai cua tre*.