Perhaps you should try some spelling variations:
so sach » so sanh, bo sach, hoc sach
co sach » bo sach, cuon sach, hoc sach
ty nang » ky nang, ty xang, ty hang
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
va cua » va chua, via cua, ca cua
cua te » cua tu
x hoi » xa hoi, o hoi, 5 hoi

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sach) OR (co sach)) ty nang ((x hoi) OR (x ho)). hieu ve pham duc va danh va cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (co sach)) ty nang ((x hoi) or (x ho)). hieu ve pham duc va danh va cua te~".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (co sach)) ty nang ((x hoi) or (x ho)). hieu ve pham duc va danh va cua te*.