Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thu sach » thuat sach, thuoc sach, thu hoach
dang hai » dang khai, hang hai, dung hai
thuc day » thuc vat
thuc dan » thuc hanh, hoc dan, thuc vat
hai cua » thai cua, dai cua, hoi cua
tu sach » su sach, te sach, tu cach
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) OR (thu sach)) ky nang co loi. hieu va lam ((thuc dan) OR (thuc day)) dang hai cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (thu sach)) ky nang co loi. hieu va lam ((thuc dan) or (thuc day)) dang hai cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (thu sach)) ky nang co loi. hieu va lam ((thuc dan) or (thuc day)) dang hai cua viet*.