Perhaps you should try some spelling variations:
ban hanh » ban hang
pham cuc » pham chuc, pham duc, pham cua
qua pham » quan pham, quy pham, qua cham
hanh de » hanh ve, hanh kem
cuc ban » cua ban, cac ban, cuu ban
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach kem
sach ty » sach y, sach tu, sach thu
de cua » le cua, te cua, dieu cua
x hoi » o hoi, x ho, 5 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 ky) OR (sach ty)) nang ((x hoi) or (xa hoi)). hieu qua pham cuc ban hanh de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang ((x hoi) OR (xa hoi)). hieu qua pham cuc ban hanh de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang ((x hoi) or (xa hoi)). hieu qua pham cuc ban hanh de cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang ((x hoi) or (xa hoi)). hieu qua pham cuc ban hanh de cua tre*.