Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, hoc sach, cuoc cach
cua triet » cua viet, su triet, va triet
doc sach » hoc sach, toc sach, dac sac
mai khoi » mai khoa, tai khoa, cac khoi
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
y nang » ky nang, ly nang, v nang
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: ((doc sach) OR (nuoc sach)) y nang ((xa hoi) OR (mai khoi)). hieu va cac duc va danh vi cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc sach) OR (nuoc sach)) y nang ((xa hoi) or (mai khoi)). hieu va cac duc va danh vi cua triet~".
• Adding a wildcard symbol may retrieve word variants: ((doc sach) OR (nuoc sach)) y nang ((xa hoi) or (mai khoi)). hieu va cac duc va danh vi cua triet*.