Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
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 va cac duc va hanh va ((cua te) OR (cua cu))~.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu va cac duc va hanh va ((cua te) or (cua cu))*.