Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » am thuc, nam thu, nam tu
ky dang » ky danh
tay hoi » tay ho, tao hoi, tay thai
dan vai » dan va, dan tai, dan vat
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
va dan » ca dan, va dao, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ((ky dang) OR (ky nang)) tay hoi. hieu qua ((nam thuc) or (nam thuoc)) va dan vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((ky dang) OR (ky nang)) tay hoi. hieu qua ((nam thuc) OR (nam thuoc)) va dan vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((ky dang) OR (ky nang)) tay hoi. hieu qua ((nam thuc) or (nam thuoc)) va dan vai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((ky dang) OR (ky nang)) tay hoi. hieu qua ((nam thuc) or (nam thuoc)) va dan vai cua tre*.