Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
nuoc gia » nuoc giai, nuoc giao, quoc gia
thanh ve » hanh ve, thanh va, thanh vien
su triet » su viet, su tien, ve triet
hieu ve » hieu va, hieu van
vu cac » va cac, tu cac, ve cac
ma hoi » mai hoi, xa hoi, me hoi
ve hoc » te hoc, va hoc, vi hoc

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: vu cac ky nang ((ma hoi) OR (ma hoa)). hieu ve hoc nuoc gia thanh ve ((cua triet) OR (su triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu cac ky nang ((ma hoi) or (ma hoa)). hieu ve hoc nuoc gia thanh ve ((cua triet) OR (su triet))~".
• Adding a wildcard symbol may retrieve word variants: vu cac ky nang ((ma hoi) or (ma hoa)). hieu ve hoc nuoc gia thanh ve ((cua triet) OR (su triet))*.