Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
danh hai » dang hai, lanh hai, manh hai
thuc day » thuc vat
thuc dan » thuc hanh, hoc dan, thuc vat
hai cua » thai cua, dai cua, hoi cua
sach ky » sac ky, sach ty, sach kem
hieu va » lieu va, hieu qua
nang co » nang cao, nang doc, nang noi
co loi » co hoi
va lam » van lam, va lap

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) OR (sach y)) nang co loi. hieu va lam ((thuc dan) OR (thuc day)) danh hai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach y)) nang co loi. hieu va lam ((thuc dan) or (thuc day)) danh hai cua viet~".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach y)) nang co loi. hieu va lam ((thuc dan) or (thuc day)) danh hai cua viet*.