Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
ban hanh » ban hang
hieu va » lieu va, hieu qua
xuc ban » duc ban, cuc ban, quoc ban
hanh le » thanh le, hanh ve, hanh de
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
co hoi » co hoc, co loi
va cam » va cham, va cac, va cao
le cuu » le cua, le huu, le cau
o hoi » o hoc, o hai, o hoa

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 y nang ((((o hoi) or (co hoi))) or (xa hoi)). hieu va cam xuc ban hanh le cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ((((o hoi) OR (co hoi))) OR (xa hoi)). hieu va cam xuc ban hanh le cuu tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ((((o hoi) or (co hoi))) or (xa hoi)). hieu va cam xuc ban hanh le cuu tre*.