Perhaps you should try some spelling variations:
ve triet » va trien, su triet
thanh do » thanh de, thanh pho, thanh hoa
hieu van » hieu va, thien van, lieu va
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
van coc » van hoc, van loc, van co
ma hoi » mai hoi, xa hoi, ma hoa
loc va » hoc va, luc va
su xac » pu xac, su cac
su sac » su sach, su cac
do ve » dao ve, do ke, de ve

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) OR (su xac)) ky tang ma hoi. hieu van coc ((loc va) or (duc va)) thanh do ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sac) OR (su xac)) ky tang ma hoi. hieu van coc ((loc va) OR (duc va)) thanh do ve triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sac) OR (su xac)) ky tang ma hoi. hieu van coc ((loc va) or (duc va)) thanh do ve triet".
• Adding a wildcard symbol may retrieve word variants: ((su sac) OR (su xac)) ky tang ma hoi. hieu van coc ((loc va) or (duc va)) thanh do ve triet*.