Perhaps you should try some spelling variations:
ban hanh » ban hang
ban danh » ban doanh, ban dan, van danh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cuu tre » cua tre, cau tren, cau treo
nang so » nang som, nang co, nang ho
va cam » va cham, va cac, va cai
so hai » son hai, su hai, so ha
di cuu » di cau, di cua, dinh cuu
va cao » va cac, va co, va dao

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 so hai. hieu ((va cam) OR (va cao)) xuc ((ban danh) or (ban hanh)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang so hai. hieu ((va cam) OR (va cao)) xuc ((ban danh) OR (ban hanh)) di cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang so hai. hieu ((va cam) OR (va cao)) xuc ((ban danh) or (ban hanh)) di cuu tre*".