Perhaps you should try some spelling variations:
manh hanh » xanh hanh, danh thanh, minh thanh
sach tham » sach nha
duc manh » suc manh, duc anh, duc minh
hieu ve » hieu va, hieu van
hanh va » hang va, hanh vi
cao duc » dao duc, cao suc, giao duc
sach ty » sach y, sach tu, sach thu
cua tre » cua te, cuu tre, cua triet
ve cao » va cao, ve bao, ve cac
va cua » va chua, via cua, ca cua
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: te ((sach ty) OR (sach tham)) nang ((x hoi) OR (x ho)). hieu ve cao duc manh hanh va cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (sach tham)) nang ((x hoi) OR (x ho)). hieu ve cao duc manh hanh va cua tre~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach tham)) nang ((x hoi) OR (x ho)). hieu ve cao duc manh hanh va cua tre*.