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
dang xay » van xay
dang van » hoang van, hang va
lai cua » dai cua, hai cua, lai chau
dan lai » dan loai, dan lap, dan lat
sach ky » sac ky, sach y, sach ty
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 xay) OR (dang van)) hoi. hieu qua ((nam thuc) or (nam thuoc)) va dan lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((dang xay) OR (dang van)) hoi. hieu qua ((nam thuc) OR (nam thuoc)) va dan lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((dang xay) OR (dang van)) hoi. hieu qua ((nam thuc) or (nam thuoc)) va dan lai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((dang xay) OR (dang van)) hoi. hieu qua ((nam thuc) or (nam thuoc)) va dan lai cua tre*.