Polak, Paweł. “Zygmunt Spira’s Remarks on Popper’s Methodology”. Philosophical Problems in Science (Zagadnienia Filozoficzne w Nauce), no. 39 (December 7, 2006): 66–91. Accessed April 26, 2024. https://zfn.edu.pl/index.php/zfn/article/view/297.