Source

File: wp-admin/includes/ms.php

function get_site_screen_help_sidebar_content() {
	return '<p><strong>' . __( 'For more information:' ) . '</strong></p>' .
		'<p>' . __( '<a href="https://wordpress.org/support/article/network-admin-sites-screen/">Documentation on Site Management</a>' ) . '</p>' .
		'<p>' . __( '<a href="https://wordpress.org/support/forum/multisite/">Support Forums</a>' ) . '</p>';
}