Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, nam thu, nam tu
cau treo » cau theo, cau tren, cau triet
tang van » dang van, hoang van, trong van
van hoi » van hoa, van hoc, van hoe
ky tang » ky nang, ky dang, kho tang
sach ky » sac ky, sach y, sach ty
dan vai » dan va, dan vat, den vai
dan tai » van tai, dan thi, han tai

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 tang van hoi. hieu qua ((nam thuc) OR (am thuc)) va ((dan vai) OR (dan tai)) cau treo~.
• Adding a wildcard symbol may retrieve word variants: toc sach ky tang van hoi. hieu qua ((nam thuc) or (am thuc)) va ((dan vai) or (dan tai)) cau treo*.