POSKROBKO, Bazyli. Letter to the Editorial Office: Sustainable Economy Based on Knowledge. Problemy Ekorozwoju, [S. l.], v. 5, n. 1, p. 153–154, 2010. Disponível em: https://ph.pollub.pl/index.php/preko/article/view/4776. Acesso em: 17 apr. 2025.