Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
hieu va » hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
ca dan » cac dan
va cuu » va cau, va chu, va huu

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: toc sach ky lang xa hoi. ((hieu va) OR (lieu va)) nam thuc ((ca dan) OR (ca dao)) va cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang xa hoi. ((hieu va) or (lieu va)) nam thuc ((ca dan) OR (ca dao)) va cuu tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. ((hieu va) or (lieu va)) nam thuc ((ca dan) OR (ca dao)) va cuu tre*.