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
cac luc » cau luc, coc luc, cac nuoc
qua cac » cua cac
lang ha » long ha
lang xa » dang xay, lang van
sac ky » cac ky, sai ky
luc va » duc va, tuc va, loc va
so sac » so sach, so dac

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: so sac ky ((lang xa) OR (lang ha)) hoi. hieu qua cac luc va hanh vi ((va triet) OR (ve triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sac ky ((lang xa) OR (lang ha)) hoi. hieu qua cac luc va hanh vi ((va triet) or (ve triet))~".
• Adding a wildcard symbol may retrieve word variants: so sac ky ((lang xa) OR (lang ha)) hoi. hieu qua cac luc va hanh vi ((va triet) or (ve triet))*.