ECE/TRANS/WP.29/GRSP/46, para. 23, ECE/TRANS/WP.29/GRSP/2009/15, ECE/TRANS/WP.29/GRSP/2009/23, ECE/TRANS/WP.29/GRSP/2009/24, ECE/TRANS/WP.29/GRSP/2010/23
Documentation: ECE/TRANS/WP.29/GRSP/46, par. 23; ECE/TRANS/WP.29/GRSP/2009/15, ECE/TRANS/WP.29/GRSP/2009/23, ECE/TRANS/WP.29/GRSP/2009/24; ECE/TRANS/WP.29/GRSP/2010/23.