GOODMAN, J. The Klein-Gordon Equation. JOURNAL OF ADVANCES IN PHYSICS, [S. l.], v. 13, n. 2, p. 4648–4650, 2017. DOI: 10.24297/jap.v13i2.5672. Disponível em: https://www.rajpub.com/index.php/jap/article/view/5672. Acesso em: 23 sep. 2025.