#!/usr/bin/perl

use Data::Dumper;

my $AoH = [ 
  { page => 'spring', chap => 'spring'},
  { page => 'spring', chap => 'spring'},
  { page => 'winter', chap => 'winter'},
  { page => 'spring', chap => 'spring'},
  { page => 'spring', chap => 'fall'},
];

my %dupes;
++$dupes{ stringify( %$_ ) } for @$AoH;;

print Dumper \%dupes;

@$AoH = grep $dupes{ stringify( %$_ ) } == 1, @$AoH;

print Dumper $AoH;

sub stringify {
  my %hash = @_;

  # explicitly name keys if you want to compare on some
  #return join '', map { $_, $hash{$_} } ( qw/ page chap / );

  # or use them all
  join '', map { $_, $hash{$_} } sort keys %hash;
}

__END__
$VAR1 = {
          'chapspringpagespring' => 3,
          'chapfallpagespring' => 1,
          'chapwinterpagewinter' => 1
        };
$VAR1 = [
          {
            'page' => 'winter',
            'chap' => 'winter'
          },
          {
            'page' => 'spring',
            'chap' => 'fall'
          }
        ];