Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
ky lang » ky dang, ky tang, tay lang
hieu ve » hieu van
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
su sac » su sach, su cac, su xac
luc va » duc va, tuc va, loc va
di va » dai va, di vao, doi va

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) OR (hieu va)) coc luc va hanh di va 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) OR (hieu va)) coc luc va hanh di va 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) OR (hieu va)) coc luc va hanh di va triet".
• Adding a wildcard symbol may retrieve word variants: su sac ((ky lang) or (ky nang)) xa hoi. ((hieu ve) OR (hieu va)) coc luc va hanh di va triet*.