Veitsman, Emil V. “THE PRINCIPLE OF EQUIVALENCE OF ENERGY SPENT ON PROCESS AND OF STEP OF TIME”. International Journal of Research -GRANTHAALAYAH 9, no. 10 (November 2, 2021): 187–190. Accessed July 3, 2024. https://granthaalayahpublication.org/journals/granthaalayah/article/view/4320.