BÁRDI, I. CONTRIBUTION TO THE VARIATIONAL METHODS FOR SOLVING STATIC AND STATIONARY ELECTROMAGNETIC FIELD PROBLEMS Periodica Polytechnica Electrical Engineering, [S. l.], v. 21, n. 2, p. 197–206, 1977. Disponível em: https://pp.bme.hu/ee/article/view/4886. Acesso em: 16 may. 2024.