PAPACHRISTOU, C. J. The Maxwell equations as a Bäcklund transformation. Advanced Electromagnetics, [S. l.], v. 4, n. 1, p. 52–58, 2015. DOI: 10.7716/aem.v4i1.311. Disponível em: http://www.aemjournal.org/index.php/AEM/article/view/311. Acesso em: 25 oct. 2025.