Perhaps you should try some spelling variations:
ban thanh » ban hang
hieu vien » hieu hien, hieu viec, thieu nien
vien dai » hien dai
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
dai duc » dao duc, dai dua, mai duc
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo
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 nang ((x hoi) OR (xa hoi)). hieu vien dai duc ((ban thanh) or (ban hanh)) vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (xa hoi)). hieu vien dai duc ((ban thanh) OR (ban hanh)) vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (xa hoi)). hieu vien dai duc ((ban thanh) or (ban hanh)) vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (xa hoi)). hieu vien dai duc ((ban thanh) or (ban hanh)) vai cuu tre*.