Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cau tren » cu tren, dau tren, ca tren
su sach » so sach, vu sach
cao duc » dao duc, cao suc, giao duc
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
va cao » va cac, va co, va dao
vi cau » va cau, ve cau, di cau
x hoi » xa hoi, o hoi, 5 hoi

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) OR (su sach)) ky nang ((x hoi) OR (x ho)). lieu va cao duc va danh vi cau tren~.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (su sach)) ky nang ((x hoi) or (x ho)). lieu va cao duc va danh vi cau tren*.