Perhaps you should try some spelling variations:
cua triet » su triet, va triet
doc sach » hoc sach, toc sach, nuoc sach
mai khoi » mai khoa, tai khoa, cac khoi
cua viet » ca viet, hoa viet, cua vat
hieu ve » hieu va, hieu van
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam

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 cam duc va hanh vi ((cua triet) OR (cua viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach y nang ((xa hoi) or (mai khoi)). hieu ve cam duc va hanh vi ((cua triet) OR (cua viet))~".
• Adding a wildcard symbol may retrieve word variants: doc sach y nang ((xa hoi) or (mai khoi)). hieu ve cam duc va hanh vi ((cua triet) OR (cua viet))*.