GRECU, Bogdan C.; RYAN, Raymond A. An integral duality formula. Mathematica Scandinavica, Berkeley, CA, United States, v. 98, n. 2, p. 229–236, 2006. DOI: 10.7146/math.scand.a-14993. Disponível em: https://journals.msp.org/mscand/article/view/704. Acesso em: 24 jul. 2026.