Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
cao hoi » cau hoi, co hoi, cao hoc
luc ban » cuc ban, luc bat, luc van
duc ban » duc tan, duc van, duc man
dua ban » dia ban, cua ban, qua ban
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
vi cua » vai cua, di cua

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: toc sach y nang cao hoi. hieu van nam ((luc ban) OR (((duc ban) OR (dua ban)))) hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang cao hoi. hieu van nam ((luc ban) or (((duc ban) OR (dua ban)))) hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang cao hoi. hieu van nam ((luc ban) or (((duc ban) OR (dua ban)))) hanh vi cua tre*.