Besler, Gabriela. “Gottlob Frege on Numbers. An Attempt to Determine the Role of the History of Mathematics in the Work of Philosophers”. Philosophical Problems in Science (Zagadnienia Filozoficzne w Nauce), no. 53 (December 12, 2013): 133–164. Accessed September 25, 2022. https://zfn.edu.pl/index.php/zfn/article/view/60.