use warnings;
use strict;
use Data::Dumper;

my %book = (
'name' => 'abc',
'author' => 'monk',
'isbn' => '123-890',
'issn' => '@issn',           
);

my %chapter = (
'title' => 'xyz',
'page' => '90',				
);

## VOIR HERE
my @temp_arr = keys %book;
@chapter{@temp_arr} = @book{@temp_arr};

print Dumper \%chapter;

print $/, $chapter{name},$/;  #prints abc