Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hieu ve » hieu va, hieu van
xuc van » duc van, luc van, vuc van
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
ve cam » ve cham, ve cac, va cam
vi cua » vai cua, di cua
o hoi » co hoi, o hoc, o hai

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: ((te sach) OR (toc sach)) ky nang o hoi. hieu ve cam xuc van hanh vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky nang o hoi. hieu ve cam xuc van hanh vi cua tre*.