Perhaps you should try some spelling variations:
cac thuc » cach thuc, cac thu, cay thuc
can thuc » dan thuc, van thuc, cay thuc
van hanh » van thanh, ban hanh, van anh
hanh cat » hanh cac, hanh luat, nhanh cay
tu sach » thu sach, su sach, te sach
cat cua » chat cua, ca cua, mat cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
me hoi » le hoi

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 ((me hoi) or (ma hoa)). hieu qua ((cac thuc) or (can thuc)) van hanh cat cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((me hoi) OR (ma hoa)). hieu qua ((cac thuc) OR (can thuc)) van hanh cat cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((me hoi) or (ma hoa)). hieu qua ((cac thuc) or (can thuc)) van hanh cat cua tre*.