Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
van dinh » van minh, van dich, xuan dinh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va dinh » va kinh, va tinh, vu dinh
cua tre » cua te, cuu tre, cua triet
me hoi » le hoi
ca cua » co cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky nang ((me hoi) or (ma hoa)). hieu va cac thuc ((va dinh) OR (van dinh)) ca cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang ((me hoi) OR (ma hoa)). hieu va cac thuc ((va dinh) OR (van dinh)) ca cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang ((me hoi) or (ma hoa)). hieu va cac thuc ((va dinh) OR (van dinh)) ca cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang ((me hoi) or (ma hoa)). hieu va cac thuc ((va dinh) OR (van dinh)) ca cua tre*.