Perhaps you should try some spelling variations:
ve triet » va trien, su triet
va triet » va thiet, va trien, cua triet
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cac luc » cau luc, coc luc, cac nuoc
hieu ve » hieu va, hieu van
ky lang » ky dang, ky tang, tay lang
ve cac » va cac, vien cac
luc va » duc va, tuc va, loc va
su sac » su sach, su cac, su xac

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ((ky lang) or (ky nang)) xa hoi. hieu ve cac luc va hanh di ((va triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ((ky lang) OR (ky nang)) xa hoi. hieu ve cac luc va hanh di ((va triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ((ky lang) or (ky nang)) xa hoi. hieu ve cac luc va hanh di ((va triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: su sac ((ky lang) or (ky nang)) xa hoi. hieu ve cac luc va hanh di ((va triet) OR (ve triet))*.