PIGNO, L. Transforms vanishing at infinity in a certain direction and semi-idempotent measures. MATHEMATICA SCANDINAVICA, [S. l.], v. 41, p. 153–158, 1977. DOI: 10.7146/math.scand.a-11709. Disponível em: https://www.mscand.dk/article/view/11709. Acesso em: 19 may. 2024.