Perhaps you should try some spelling variations:
ban thanh » ban hang
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
vien dai » hien dai
vien cac » vien bach, vien da, gian cac
sach ky » sac ky, sach y, sach ty
vai cuu » vai cua
cuu tre » cua tre, cau tren, cau treo
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang x hoi. hieu ((vien cac) OR (vien dai)) duc ((ban thanh) or (ban hanh)) vai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang x hoi. hieu ((vien cac) OR (vien dai)) duc ((ban thanh) OR (ban hanh)) vai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang x hoi. hieu ((vien cac) OR (vien dai)) duc ((ban thanh) or (ban hanh)) vai cuu tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang x hoi. hieu ((vien cac) OR (vien dai)) duc ((ban thanh) or (ban hanh)) vai cuu tre*.