Query WP1

// WP_Query arguments
$args = array(
	'post_type'              => array( 'working-papers', ' rivista' ),
	'nopaging'               => false,
	'paged'                  => '$paged',
	'posts_per_page'         => '5',
	'posts_per_archive_page' => '5',
	'ignore_sticky_posts'    => false,
	'order'                  => 'DESC',
	'orderby'                => 'date',
);

// The Query
$custom_query = new WP_Query( $args );