Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu ve » hieu van
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
y nang » ky nang, ly nang, v nang
cua te » cua tu
cua cu » cua chu, cua cau, cua su
x hoi » xa hoi, o hoi, x ho

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