SJÖLN, Per. An inequality for convex curves in the plane. Mathematica Scandinavica, Berkeley, CA, United States, v. 40, p. 293–300, 1977. DOI: 10.7146/math.scand.a-11696. Disponível em: https://journals.msp.org/mscand/article/view/1950. Acesso em: 25 jul. 2026.