Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
dinh vai » dinh van, dinh vi, dinh va
vai cua » dai cua, hai cua, lai cua
va dinh » van dinh, va kinh, va tinh
thuc va » thuc vat, thuc dan, thuc day
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
hieu va » hieu qua
so hai » son hai, su hai, so ha
ro hai » co hai, o hai, do hai

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: tu sach ky nang ((ro hai) OR (so hai)). ((hieu va) OR (lieu va)) am thuc va dinh vai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((ro hai) or (so hai)). ((hieu va) OR (lieu va)) am thuc va dinh vai cua viet~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((ro hai) or (so hai)). ((hieu va) OR (lieu va)) am thuc va dinh vai cua viet*.