Perhaps you should try some spelling variations:
nam thuoc » nam thu, cay thuoc, va thuoc
nha thuoc » nha nuoc, nhan thuc, nha hoc
nam thuc » am thuc, nam thu, nam tu
toc sach » hoc sach, doc sach, thuoc sach
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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 lang xa hoi. hieu va ((nam thuc) or (((nam thuoc) OR (nha thuoc)))) va dan vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang xa hoi. hieu va ((nam thuc) OR (((nam thuoc) OR (nha thuoc)))) va dan vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky lang xa hoi. hieu va ((nam thuc) or (((nam thuoc) OR (nha thuoc)))) va dan vai cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang xa hoi. hieu va ((nam thuc) or (((nam thuoc) OR (nha thuoc)))) va dan vai cua tre*.