Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va cham » va chat, va tham
cua tre » cuu tre, cua triet, dua tren
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
doc va » duoc va, duc va, loc va
cua te » cua tu
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: thu sach y nang o hoi. lieu va cham ((doc va) or (hoc va)) hanh vi ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang o hoi. lieu va cham ((doc va) OR (hoc va)) hanh vi ((cua tre) OR (cua te)).
• Adding a wildcard symbol may retrieve word variants: thu sach y nang o hoi. lieu va cham ((doc va) or (hoc va)) hanh vi ((cua tre) or (cua te))*.