SZTUMSKI, Wiesław. For Further Social Development, Peaceful, Safe and Useful for People. Problemy Ekorozwoju, [S. l.], v. 14, n. 2, p. 25–32, 2019. Disponível em: https://ph.pollub.pl/index.php/preko/article/view/5076. Acesso em: 22 jul. 2024.