CHAKRAVORTY, Kanai Lal. Mass of a System of Material Particles Including Photons. International Astronomy and Astrophysics Research Journal, [S. l.], v. 3, n. 1, p. 147–150, 2021. Disponível em: https://www.journaliaarj.com/index.php/IAARJ/article/view/46. Acesso em: 5 sep. 2026.