POLAK, P. Zygmunt Spira’s remarks on Popper’s methodology. Philosophical Problems in Science (Zagadnienia Filozoficzne w Nauce), [S. l.], n. 39, p. 66–91, 2006. Disponível em: https://zfn.edu.pl/index.php/zfn/article/view/297. Acesso em: 19 may. 2022.