Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
ca nuoc » cap nuoc, cac nuoc, cua nuoc
va danh » va dinh, va hanh, dia danh
qua ca » qua cac, qua cua, qua cai
va dan » ca dan, va dao, va dau
ca cua » co cua

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: te sach ky ((mang may) OR (nang ma)) hoi. hieu qua ca nuoc ((va danh) OR (va dan)) ca cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((mang may) or (nang ma)) hoi. hieu qua ca nuoc ((va danh) OR (va dan)) ca cua viet~".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((mang may) or (nang ma)) hoi. hieu qua ca nuoc ((va danh) OR (va dan)) ca cua viet*.