Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, can thuc
day danh » day manh, dao danh, day dan
dai danh » dai dang, dao danh, loai danh
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
ca cuu » cap cuu, cua cuu, ca cua

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

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