Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
cao duc » dao duc, cao suc, giao duc
va hanh » va thanh, va danh, ban hanh
cuu tre » cua tre, cau tren, cau treo
y nang » ky nang, ly nang, v nang
ve cao » va cao, ve bao, ve cac
vi cuu » vi luu, vinh cuu
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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: tu sach y nang ((x hoi) OR (o hoi)). hieu ve cao duc ((va hanh) OR (van hanh)) vi cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang ((x hoi) or (o hoi)). hieu ve cao duc ((va hanh) OR (van hanh)) vi cuu tre~".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((x hoi) or (o hoi)). hieu ve cao duc ((va hanh) OR (van hanh)) vi cuu tre*.