Prykarpatsky, A. K. “The Quantum Fermionic Charged Particle Self-Interaction Problem Within the Fock Multitime and Feynman Proper Time Paradigms”. Ukrainian Journal of Physics 62, no. 2 (December 23, 2018): 172. Accessed March 28, 2024. https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2018719.