AR finder with include only specific value

finally i solved with this:

@users = User.find(:all, :include => :langs)

and on wiew modified with:

<td><%=h item.langs.find_by_langcode(I18n.default_locale.to_s).title
%></td>
<td><%=h item.langs.find_by_langcode(I18n.default_locale.to_s).langcode
%></td>

this solution work, i hope right also in terms of performances