Perhaps you should try some spelling variations:
xay trong » cay trong, day trong, gay trong
nam thuc » nam thuoc, am thuc, nam thu
thuc xay » thuc day, tuc xay, thuat xay
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
doi cua » dai cua
hoi cua » hoi chuc
va nam » van nam, ha nam, va nay

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: so sach ky ((nang xa) OR (nang x)) hoi. hieu va nam thuc xay trong ((doi cua) OR (hoi cua)) triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ky ((nang xa) or (nang x)) hoi. hieu va nam thuc xay trong ((doi cua) OR (hoi cua)) triet~".
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang xa) or (nang x)) hoi. hieu va nam thuc xay trong ((doi cua) OR (hoi cua)) triet*.