$$rf_s .= 'foo' ;

 push(@$rf_a , "BAR") ;
 $$rf_a[0] = 'bar' ;
 
 $$rf_h{b} = 'foo' ;
 foreach my $Key ( keys %{$rf_h} ) {
   my $Value = $$rf_h{$Key} ;
   print "$Key = $Value\n" ;
 }