SARANEN, J. On a inequality of Friedrichs. MATHEMATICA SCANDINAVICA, [S. l.], v. 51, p. 310–322, 1982. DOI: 10.7146/math.scand.a-11983. Disponível em: https://www.mscand.dk/article/view/11983. Acesso em: 28 apr. 2024.