Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
lang van » dang van, tang van, hoang van
dang xay » dang van, van xay
vai cuu » vai cua
vat dan » van dan, vat ran, hat dan
qua nam » quan nam, cua nam, quang nam
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
va dan » ca dan, va dao, va dau

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