Ewertowski, Stefan, and Arkadiusz Modrzejewski. “Sustainable Development’s Issues in the Light of Karol Wojtyła – John Paul II’s Political Philosophy and Theology”. Problemy Ekorozwoju, vol. 8, no. 1, Jan. 2013, pp. 73-82, https://ph.pollub.pl/index.php/preko/article/view/4862.