Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
cua triet » su triet, va triet
cua viet » ca viet, hoa viet, cua vat
dao duc » giao duc, tao duoc
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
hieu ve » hieu va, hieu van
ve dao » de dao, va dao, ve bao
va anh » van anh, va danh, va hanh
anh va » hanh va
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ly nang ((x hoi) OR (o hoi)). hieu ve dao duc va anh va ((cua triet) or (cua viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ly nang ((x hoi) OR (o hoi)). hieu ve dao duc va anh va ((cua triet) OR (cua viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ly nang ((x hoi) OR (o hoi)). hieu ve dao duc va anh va ((cua triet) or (cua viet))".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ly nang ((x hoi) OR (o hoi)). hieu ve dao duc va anh va ((cua triet) or (cua viet))*.