Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
doc sach » hoc sach, toc sach, nuoc sach
mai khoi » mai khoa, tai khoa, cac khoi
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
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 y nang ((xa hoi) OR (mai khoi)). hieu ve pham duc ((va hanh) OR (va danh)) vi cua triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach y nang ((xa hoi) or (mai khoi)). hieu ve pham duc ((va hanh) OR (va danh)) vi cua triet~".
• Adding a wildcard symbol may retrieve word variants: doc sach y nang ((xa hoi) or (mai khoi)). hieu ve pham duc ((va hanh) OR (va danh)) vi cua triet*.