WAROT, P. P. Sławomir Cenckiewicz, Piotr Gontarczyk, The secret Police and Lech Wałęsa. Contribution to his biography. Echa Przeszłości, [S. l.], n. IX, 2019. Disponível em: https://czasopisma.uwm.edu.pl/index.php/ep/article/view/3545. Acesso em: 27 jul. 2024.