ASPLUND, Edgar. Comparison Between Plane Symmetric Convex Bodies and Parallelograms. Mathematica Scandinavica, Berkeley, CA, United States, v. 8, p. 171–180, 1960. DOI: 10.7146/math.scand.a-10606. Disponível em: https://journals.msp.org/mscand/article/view/2739. Acesso em: 25 jul. 2026.