HANSEN, Frank; PECARIC, Josip; PERIC, Ivan. Jensen’s operator inequality and its converses. MATHEMATICA SCANDINAVICA, [S. l.], v. 100, n. 1, p. 61–73, 2007. DOI: 10.7146/math.scand.a-15016. Disponível em: https://www.mscand.dk/article/view/15016. Acesso em: 6 dec. 2025.