If the original order isn't important, here's one alphabetically sorted: 
use strict;
use warnings;

my $array = [
   {
     'name' => 'Discount',
     'reference' => '100       ',
     'type' => 'Paper'
   },
   {
     'name' => 'Documents',
     'reference' => '100       ',
     'type' => 'Paper'
   },
   {
     'name' => 'Money',
     'reference' => '340       ',
     'type' => 'Plastic'
   },
   {
     'name' => 'State',
     'reference' => '40        ',
     'type' => 'Cotton'
   },
   {
     'name' => 'Slice',
     'reference' => '30        ',
     'type' => 'Cotton'
   },   {
     'name' => 'Part',
     'reference' => '45        ',
     'type' => 'Cotton'
   },
];

my %hash;
$hash{$_->{'type'}}{$_->{'name'}} = $_->{'reference'} for @$array;

print "Results:\n";
for my $k1 (sort keys %hash) {
    print "    $k1:\n";
    for my $k2 (sort keys %{$hash{$k1}}) {
        print "        $k2 - $hash{$k1}{$k2}\n";
    }
}

[download]
Output: 
Results:
    Cotton:
        Part - 45        
        Slice - 30        
        State - 40        
    Paper:
        Discount - 100       
        Documents - 100       
    Plastic:
        Money - 340

[download]

In reply to Re: Accessing this array ref. by TJPride
in thread Accessing this array ref. by Anonymous Monk

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