ALBRECHT, F.; DIAMOND, H. G. An Extremal Problem Involving Functions and Their Inverses. MATHEMATICA SCANDINAVICA, [S. l.], v. 29, p. 328–336, 1971. DOI: 10.7146/math.scand.a-11059. Disponível em: https://www.mscand.dk/article/view/11059. Acesso em: 30 apr. 2024.