DLOUHÁ, J. Environment for Europe. Envigogika, Praha, Czech Republic, v. 2, n. 1, 2007. DOI: 10.14712/18023061.206. Disponível em: https://www.envigogika.cuni.cz/index.php/Envigogika/article/view/206. Acesso em: 23 apr. 2021.