Karol Szostek, and Roman Szostek. “The Existence of a Universal Frame of Reference, in Which It Propagates Light, Is Still an Unresolved Problem of Physics”. Jordan Journal of Physics 15, no. 5 (May 6, 2025). Accessed May 10, 2025. https://jjp.yu.edu.jo/index.php/jjp/article/view/1027.