Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
thanh hai » thanh phan, thanh hoa, thanh san
hai cua » thai cua, dai cua, hoi cua
duc van » duc va, duc tan, duc manh
duc ban » duc tan, dua ban, duc man
cua tre » cua te, cuu tre, cua triet
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang o » nang co, nang ho, nang ro
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: thuat sach ty nang o hoi. hieu ((va gia) OR (va giai)) ((duc ban) OR (duc van)) thanh hai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach ty nang o hoi. hieu ((va gia) or (va giai)) ((duc ban) OR (duc van)) thanh hai cua tre~".
• Adding a wildcard symbol may retrieve word variants: thuat sach ty nang o hoi. hieu ((va gia) or (va giai)) ((duc ban) OR (duc van)) thanh hai cua tre*.