GRYGIEL, Wojciech. The objective status of an observer in quantum mechanics according to Roger Penrose. Philosophical Problems in Science (Zagadnienia Filozoficzne w Nauce), [S. l.], n. 45, p. 45–61, 2009. DOI: 10.59203/zfn.45.192. Disponível em: https://www.zfn.edu.pl/index.php/zfn/article/view/192. Acesso em: 26 nov. 2025.