CAO, Yucheng. A New Journal’s Fifth Anniversary: Problemy Ekorozwoju/Problems of Sustainable Development. Problemy Ekorozwoju, [S. l.], v. 6, n. 2, p. 7–10, 2011. Disponível em: https://ph.pollub.pl/index.php/preko/article/view/4778. Acesso em: 22 jul. 2024.