get tags in $args?

Hi, I have this code for getting content from a specific post type. Do you know how can I add a rule in order to get just related content by tags?

$args = array(
			'post_type' => 'books',
			'posts_per_page' => 6,
			'orderby'=>'date',
			'order'=>DESC,); 	

			query_posts( $args );
			while ( have_posts() ) {
			the_post();

Thanks a lot!

[please continue with the original topic: http://wordpress.org/support/topic/how-to-get-related-posts-by-tags?replies=1 ]