Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cua tre » cuu tre, cua triet, dua tren
y nang » ky nang, ly nang, v nang
va cau » van cau, va cac, va dau
luc va » tuc va, loc va
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang x hoi. hieu va cau ((luc va) or (duc va)) hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang x hoi. hieu va cau ((luc va) OR (duc va)) hanh vi ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: tu sach y nang x hoi. hieu va cau ((luc va) or (duc va)) hanh vi ((cua tre) or (cua te))*.