Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua triet » cua viet, su triet, va triet
thanh di » thanh doi, thanh de, thanh do
nam thuc » nam thuoc, nam thu, nam tu
su viet » so viet
nang ho » nang hoc, nang co, tang ho
hieu ve » hieu va, hieu van
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky
ho hoi » hoc hoi, hoa hoi, hoi hoi

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: su sac ky nang ho hoi. hieu ve ((nam thuc) OR (am thuc)) ban thanh di ((cua triet) OR (su viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ho hoi. hieu ve ((nam thuc) OR (am thuc)) ban thanh di ((cua triet) or (su viet))~".
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ho hoi. hieu ve ((nam thuc) OR (am thuc)) ban thanh di ((cua triet) or (su viet))*.