Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cap nuoc » dat nuoc
hieu le » hieu ve, hieu he, hieu ly
lua tre » cua tre, luy tre, dua tren
y nang » ky nang, ly nang, v nang
le cap » le cau
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
va lua » va luat, ca lua, vi lua
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.

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang ((x hoi) or (o hoi)). hieu le cap nuoc va dan va lua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang ((x hoi) OR (o hoi)). hieu le cap nuoc va dan va lua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach y nang ((x hoi) or (o hoi)). hieu le cap nuoc va dan va lua tre*.