POLAK, Paweł Jan. Virtual entities – a part of our reality. Philosophical Problems in Science, [S. l.], n. 68, p. 306–310, 2020. DOI: 10.59203/zfn.68.521. Disponível em: https://zfn.edu.pl/index.php/zfn/article/view/521. Acesso em: 8 dec. 2025.