de Sitter, Willem. “On the Relativity of Inertia. Remarks Concerning Einstein’s Latest Hypothesis”. Philosophical Problems in Science (Zagadnienia Filozoficzne w Nauce), no. 63 (December 28, 2017): 205–222. Accessed July 1, 2025. https://zfn.edu.pl/index.php/zfn/article/view/417.