%chapter = 
( 
    'book'=> {
        'name' => 'abc',
        'author' => 'monk',
        'isbn' => '123-890',
        'issn' => '@issn',        
    },
    'title' => 'xyz',
    'page' => '90',   
);

$value = $chapter{'book'}{'name'};
print ":$value:";