Perhaps you should try some spelling variations:
te sach » toc sach
cao hoi » cau hoi, co hoi, tao hoi
cao hoc » co hoc, cho hoc, chat hoc
duc van » duc va, duc tan, duc manh
van anh » van thanh, tuan anh, van minh
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
va nam » ha nam, va nay
anh vi » hanh vi, anh va, anh ve
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: te sach y nang ((cao hoi) OR (cao hoc)). hieu ((va nam) OR (van nam)) duc van anh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y nang ((cao hoi) or (cao hoc)). hieu ((va nam) OR (van nam)) duc van anh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((cao hoi) or (cao hoc)). hieu ((va nam) OR (van nam)) duc van anh vi cua tre*.